My doctor told me that birth control pills contain small amounts of estrogen and progesterone, and these hormones prevent me from ovulating. i don't understand how giving me these hormones in a pill would prevent me from ovulating. i assume that this has something to do with the levels of the gonadotropins that i asked about earlier. can you explain this to me? \

Estrogen and progesterone stabilize a woman's natural hormone levels, and prevent estrogen from peaking mid-cycle. Also a  high level of progesterone is maintained which prevents secretions of FSH and LH. The result is that no new egg follicles are developed and no ovulation occurs.

The level of estrogen in your body is still increasing and it eventually causes a rapid rise in luteinising hormone (often called the ‘LH surge‘). This LH surge gives the ripening egg the final push it needs to fully ripen and be released from the follicle. This process is known as ovulation.

Many women think that they ovulate on day 14, but this isn‘t always the case. Your day of ovulation will vary depending on your cycle length. Some women feel a twinge of pain when they ovulate, but many feel no sensation at all and there‘s no other sign that you are ovulating.

Dna strands are split apart to allow an opening for replication. the opening has two replication forks so synthesis goes toward them in 5' to 3' direction.