Implantation is when a fertilized egg, which has divided, multiplied, and turned into a cluster of cells called a blastocyst, attaches to the uterine wall. Generally, this happens approximately between six to 12 days after ovulation, and once it does, a pregnancy has officially begun.
The timing of ovulation may seem like a detail that only concerns an OB/GYN, but knowing when implantation occurs is important for those trying to conceive. Implantation timing influences both how to time sex for pregnancy and when to take a pregnancy test to ensure the most accurate results. Learn more about implantation and its role in pregnancy and when implantation occurs.
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Ovulation and Implantation Timing
Implantation happens when a fertilized egg burrows into the uterine lining and begins to grow. When this can occur for each person is dependent on their overall cycle length, which is not the same for everyone, and when the egg was fertilized.
Generally, ovulation happens about 14 days prior to the beginning of menstruation. An egg is released from either the left or right ovary, after which it will live for about 24 hours unless it is fertilized. If fertilization does not happen, the uterine lining is sloughed off, and menstruation begins.
You don't have to have sex at the exact moment of ovulation—just close to it. In fact, ideally, you will have sex a few times in the days before ovulation occurs. Sperm can live for up to five days inside the body and meet up with an egg making its way through the fallopian tube to the uterus. Sperm then breaks through the barriers surrounding the egg to fertilize it.
The fertilized egg then travels the remaining way to the uterus, a journey that takes several days. Implantation itself usually occurs between six to 12 days after the egg is fertilized.
|Approximate Timing of Ovulation and Implantation by Cycle Length|
|Cycle Length||Ovulation and Fertilization||Implantation|
|28 days||Day 14||Day 20 to 24|
|30 days||Day 16||Day 22 to 26|
|32 days||Day 18||Day 24 to 28|
8 Signs of Ovulation That Help Detect Your Most Fertile Time
Implantation and Pregnancy Tests
Pregnancy tests are very specific about their timing because they test for the presence of a hormone called human chorionic gonadotropin (hCG). Because hCG is produced by a developing placenta, the body cannot produce it until after implantation happens.
This is why the levels of hCG in the body vary depending on how long after implantation you take a pregnancy test. In the very early stages of pregnancy, there is very little hCG in the urine because there hasn't been enough time between implantation and testing for it to build up in the body.
A pregnancy that has been implanted four days prior to the expected start of your period is just beginning to send signals to the body. Testing this early is usually not recommended unless there is a very specific reason, as false negatives can occur.
An Overview of Home Pregnancy Tests
Signs and Symptoms of Implantation
Most people do not have any specific signs or symptoms to indicate that implantation has occurred. However, some people may experience the following indicators that implantation has occurred.
A small number of pregnant people experience a phenomenon calledimplantation bleeding. Implantation bleeding usually involves only very light spotting. But occasionally, it can be confused for a menstrual period, or even a first-trimester miscarriage, because of its timing.
Implantation Cramps: Symptoms, Timing, and FAQs
For people tracking their basal body temperature (BBT) on a fertility calendar, a brief, one-day drop in BBT can occur during implantation. This is commonly referred to as an implantation dip and can indicate pregnancy in those who chart their BBT.
Early Pregnancy Symptoms
Typically, signs or symptoms of pregnancy do not occur immediately following implantation. Although not always the case, most people start to experience early pregnancy symptoms like nausea, fatigue, and breast tenderness around the time of their missed period.
Problems With Implantation
Most often implantation of an embryo happens without a hitch, but occasionally a problem may occur.
Occasionally, implantation occurs outside of the uterus. This is anectopic pregnancy. An ectopic pregnancy is often called tubal pregnancybecause many of these pregnancies occur in the fallopian tube. That said, some of these pregnancies also occur in places like the ovary, abdomen, or cervix.
When the egg is not within the confines of the uterus, the pregnancy is not viable. Ectopic pregnancies are also dangerous for the pregnant person, as they can cause severe hemorrhaging.
Treatment can include medication and/or surgery, which may involve the removal of the fallopian tube. Ectopic pregnancies can occasionally have ramifications in future pregnancies, including recurrence of ectopic pregnancy. However, most people go on to have subsequent successful pregnancies.
When an embryo implants at the latter end of the six- to 10-day implantation window, it is called late implantation. More specifically, late implantation is typically defined as that which occurs between the 8th and 10th day.
Implantation can occur successfully during this period and it is usually not a cause for concern. However, some studies indicate an incremental increase in the likelihood of miscarriage the later the implantation happens, although the strength of this association is not yet fully understood.
While you can't control when or where an embryo implants, maternal smoking and advanced maternal age may make later implantation more likely.
Failure to Implant
Another issue that can occur is the failure of the embryo to implant. If this happens during a typical cycle of trying to get pregnant, you will likely have no way of knowing.
However, when using fertility treatments, you may know when an embryo does not successfully implant. When this happens three or more times in failed in vitro fertilization (IVF) attempts it is called recurrent implantation failure (RIF).
The causes of failure to implant are not always known but are thought to be a combination of uterine abnormalities (such as endometriosis, polyps, or infection) and/or embryonic abnormalities (often chromosomal). Additional risk factors related to the parents may include smoking, age, body mass index, and stress.
A Word From Verywell
Implantation is a key milestone of the pregnancy journey. Understanding how and when it occurs can help you conceive and test.
The process of conception can seem daunting, but know that as long as you regularly have sex, your chances of getting pregnant within a year are generally very high. In fact, 85% or more of couples conceive within one year of trying, with rates even higher for those younger than 30.
Week 1 of Your Pregnancy
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Su RW, Fazleabas AT. Implantation and establishment of pregnancy in human and nonhuman primates.Adv Anat Embryol Cell Biol. 2015;216:189-213. doi:10.1007/978-3-319-15856-3_10
National Collaborating Centre for Women’s and Children’s Health. Initial advice to people concerned about delays in conception. In: Fertility: Assessment and Treatment for People with Fertility Problems.
Reed BG, Carr BR. The normal menstrual cycle and the control of ovulation. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext.
MedlinePlus. Pregnancy - identifying fertile days.
Steiner AZ, Pritchard DA, Young SL, Herring AH. Peri-implantation intercourse lowers fecundability.Fertil Steril. 2014;102(1):178–182. doi:10.1016/j.fertnstert.2014.03.017
Food and Drug Administration. Pregnancy.
Promes SB, Nobay F. Pitfalls in first-trimester bleeding. Emerg Med Clin North Am. 2010;28(1):219-34, x. doi:10.1016/j.emc.2009.10.005
Sivalingam VN, Duncan WC, Kirk E, Shephard LA, Horne AW. Diagnosis and management of ectopic pregnancy.J Fam Plann Reprod Health Care. 2011;37(4):231–240. doi:10.1136/jfprhc-2011-0073
Stremick JK, Couperus K, Ashworth SW. Ruptured tubal ectopic pregnancy at fifteen weeks gestational age.Clin Pract Cases Emerg Med. 2019;3(1):62–64. doi:10.5811/cpcem.2019.1.40860
Jukic AM, Weinberg CR, Baird DD, Wilcox AJ. The association of maternal factors with delayed implantation and the initial rise of urinary human chorionic gonadotrophin.Hum Reprod. 2011;26(4):920-926. doi:10.1093/humrep/der009
Bashiri A, Halper KI, Orvieto R. Recurrentimplantationfailure-update overview on etiology, diagnosis, treatment and future directions.Reprod Biol Endocrinol. 2018;16(1):121. doi:10.1186/s12958-018-0414-2
National Institutes of Health. How common is infertility?.
By Krissi Danielsson
Krissi Danielsson, MD is a doctor of family medicine and an advocate for those who have experienced miscarriage.
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The first sign of implantation is implantation bleeding which occurs 6-12 days post conception. If the implantation is successful, spotting or light cramping can be experienced. If unsuccessful, your period will start.How long does implantation take to start? ›
Implantation. Once the embryo reaches the blastocyst stage, approximately five to six days after fertilization, it hatches out of its zona pellucida and begins the process of implantation in the uterus.How does a woman feel during implantation? ›
Implantation cramping and bleeding
Women may experience cramps very early on in pregnancy. These are due to implantation, which is when the fertilized egg attaches to the lining of the uterus. Implantation cramps may occur a few days after ovulation, and many women say that they feel cramps around 5 DPO.
It's recommended that you avoid strenuous physical activities like heavy weight-lifting or high-impact cardio during your two-week wait as it could lead to uterine contractions and affect the implantation process. After the first few days of our waiting period, you can do some light exercising like walking or swimming.Where do you feel implantation pain? ›
Most women experience implantation cramps in their lower abdomen or lower back. On occasion these cramps will be isolated to one side of the body and be felt within the lower right or lower left side of your abdomen.What does implantation pain feel like? ›
The sensation is different from person to person, but in most cases, they feel like mild cramps, usually dull and aching, or light twinges. Some people also describe feeling a prickling, tingling, or pulling sensation. The sensations may come and go or last for one to two days before disappearing.Can you test positive before implantation? ›
If you take a pregnancy test before implantation occurs, the test will tell you that you're not pregnant, even if you have actually conceived. Since hCG is not yet in your system, the test cannot detect it.Where do you feel implantation pain? ›
Most women experience implantation cramps in their lower abdomen or lower back. On occasion these cramps will be isolated to one side of the body and be felt within the lower right or lower left side of your abdomen.What is discharge like after implantation? ›
Cervical mucus after conception
After implantation (when a fertilized egg attaches to your uterus), mucus tends to be clear, thick, and gummy. Some people experience implantation bleeding, or spotting, which can occur 6 to 12 days after conception.
In summary, implantation occurred 8 to 10 days after ovulation in most healthy pregnancies. The proportion ending in early loss increased when implantation occurred later.
- Cramps. The earlier days of pregnancy may include abdominal cramping. ...
- Spotting. This may be implantation bleeding and typically happens around 6 to 12 days after the egg gets fertilized. ...
- Nausea. ...
- Tender breasts.