How many days does it take for a fertilized egg to implant?

Implantation of the fertilized egg typically occurs 6–7 days after conception; however, at this stage the gestational sac is extremely small and cannot be detected by ultrasound.

Following successful implantation, human chorionic gonadotropin (hCG) levels in the blood rise significantly, allowing pregnancy to be confirmed via hCG testing.

After implantation, some women may experience a drop in basal body temperature, light vaginal spotting, or breast tenderness.

A transient decline in basal body temperature may occur in particularly sensitive individuals following implantation, due to fluctuations in progesterone that affect the hypothalamic thermoregulatory center.

Implantation within the uterine cavity may irritate the endometrium, leading some women to experience light vaginal bleeding—often appearing as pink or brownish streaks and typically scant in volume.

Hormonal changes—particularly rising progesterone levels—following implantation can cause breast tenderness or discomfort.

It is important to note that after successful implantation, women should ensure adequate rest, maintain a balanced diet, and abstain from sexual intercourse.