Pregnancy at week 3, implantation takes place .so what’s happening exactly?
After conception, the fertilized egg (called a zygote )grows by dividing several times over the next few days while it moves through the uterine tube into the uterus .on day 6 -8, right at the beginning of week three, the fertilized egg is called a blastocyst.
The blastocyst is divided into layers, an inner layer that will eventually become the fetus and an outer layer (trophoblast) that becomes the placenta.
When the blastocyst implants into the endometrium ‘it starts producing human chorionic gonadotropin (hCG).HCG is the substance detected by pregnancy tests. It is also responsible for nausea and other pregnancy symptoms you may be experiencing. It stimulates the release of progesterone, and the ovaries stop generating new eggs.
From this point until the end of the pregnancy, your menstrual cycle pauses.