When does implantation occur? What are signs of implantation?

Normally, implantation occurs 7 to 10 days after ovulation. Before implantation, fertilized egg is just free-floating in the womb. At the time of fertilization, incipient embryo (or blastocyst) is just a cluster of multiple cells. Blastocyst must develop and grow through several phases and stages before it can be attached to the side of womb.

Pregnancy takes place at the moment of implantation, while placental tissue starts to secret hormone hCG, when early pregnancy test can be taken.

There are a couple of signs to indicate implantation,

1. Positive pregnancy test. As false positive pregnancy test result rarely happens, positive early pregnancy test result gives a solid confirmation of implantation.
2. Some women may experience implantation bleeding, a very light spotting which may occur right after embyo implants in the lining of the uterus. Typical color of the spotting is brown or possibly reddish.