Nidation: what it is, when it occurs and symptoms

Implantation corresponds to the process of implantation of the egg fertilized by sperm into the wall of the uterus, the endometrium, giving rise to the initial stage of pregnancy. Nidation can happen up to 7 days after fertilization, because the fertilized egg must be moved through the fallopian tube towards the uterus for implantation and pregnancy to develop.

In most cases, implantation does not lead to the appearance of signs or symptoms, however some women may experience light pink or brown bleeding, which can last a few hours or up to 3 days. Additionally, some women may experience mild cramps and a stitching sensation in the belly, for example.

Therefore, to confirm that implantation has occurred, it is important to take a pharmacy pregnancy test to check whether the beta-HCG hormone is detectable in the urine. If positive, it is recommended to carry out a blood test to confirm the pregnancy and the week of gestation, in addition to being essential to consult the gynecologist so that monitoring can begin. See more about tests to detect pregnancy.

When nesting happens

For implantation to occur, the woman must have sexual intercourse without using a condom during the ovulatory period. In this way, it is possible for the sperm to come into contact with the egg released by the woman in the uterine tube, fertilization and movement of the fertilized egg towards the uterus, where implantation takes place.

In general, implantation takes place 5 to 7 days after the fertile period. To find out when your fertile period is and your possible breeding date, enter your data into the calculator below:

In the case of assisted reproduction, implantation takes place from the moment the woman’s egg comes into contact with a viable sperm, which can happen outside or inside the uterus. Understand how assisted reproduction works.

Nesting symptoms

Normally implantation does not lead to the appearance of signs or symptoms, however some women with more sensitive organisms may present symptoms as soon as the fertilized egg implants in the uterine wall. Therefore, in some cases it is possible to notice slight pink or brown bleeding, of little intensity and which can last up to 3 days. Learn more about implantation bleeding.

Furthermore, some women may experience symptoms typical of early pregnancy, such as mild cramps, a feeling of pain in the belly, more specifically in the lower abdomen, and nausea, in some cases. These symptoms are directly related to the hormonal changes characteristic of this period, such as an increase in the level of circulating beta-HCG and progesterone.