Where Does Implantation Occur In The Uterus?

Where Does Implantation Occur In The Uterus? Implantation begins with apposition of the blastocyst at the uterine epithelium, generally about 2-4 days after the morula enters the uterine cavity. The implantation site in the human uterus is usually in the upper and posterior wall in the midsagittal plane. Which part of uterus does implantation occur?