period. ovulation?

Hello Anonymous,
Yes, the earlier onset of your period is because you stopped taking your active birth control pills four days earlier.

Most birth control pills contain synthetic forms of two female hormones: estrogen and progestin. These synthetic hormones stabilize a woman's natural hormone levels and prevent estrogen from peaking mid-cycle. Subsequently, the pituitary gland does not release the hormones that normally cause the ovaries to release mature eggs. Birth control pills prevent pregnancy mainly by stopping ovulation.

When you stop taking the active birth control pills, the break from the synthetic hormones triggers your monthly bleeding that mimics a menstrual period.

To answer your second question, yes, your ovulation time may be altered because you stopped taking your pills earlier. It may take one month cycle to regulate.

One option for tracking your ovulation include using an ovulation calendar. The American Pregnancy Association website offer a guide: http://www.americanpregnancy.org/gettingpregnant/ovulationcalendar.html.
Take a look at the EmpowHer Getting Pregnant page for helpful articles, including top online ovulation and fertility tools:
https://www.empowher.com/getting-pregnant

Good Health,

Maryann