Welcome to Week 2 of Your Pregnancy!
Fertilization & Dates:
Fertilization does not always announce itself so, the first day of your last menstrual period is how pregnancy dates are calculated even though you are not yet pregnant.
Initially, under the influence of follicle stimulating hormone an egg develops inside a mature ovarian follicle. Serum estrogen rises by the follicle causing the functional layer of the endometrium which, is the lining of your womb and also the layer closest to the inner uterine cavity to proliferate or become thicker. The spiral arteries in this area elongate and the uterine glands increase in number and length. As a result there is an abrupt surge in luteinizing hormone instructed by the pituitary gland and causes ovulation. The pituitary gland is an endocrine gland that is located at the base of your brain and is about the size of pea.
What is Ovulation:
Ovulation is when the follicle swells and bursts releasing the egg from the dominant follicle. You have two ovaries but in any given cycle ovulation only occurs from just one of them, and usually occurs on day 14 of your cycle. After ovulation the remaining follicle within the ovary collapses and becomes the corpus luteum of pregnancy. This corpus luteum produces progesterone and a small amount of estrogen. All this hormonal activity is responsible for changes in the lining of the womb as it enters the secretory phase so called because the uterine glands now secrete and continue to thicken as a result of glandular and vascular growth all this preparing for implantation of a fertilized egg.