Withdrawal bleeding refers to the bleeding that occurs in someone using oral contraceptives during the week that she is taking inactive/placebo pills -- this is when the woman taking the pill menstruates.
Unlike normal menstruation, it is not caused by the natural cycling of hormones that surrounds ovulation, causing the lining of the uterus to be built up (for implantation of a fertilized egg) and eventually shed; rather, it is caused by suddenly taking away an external source of estrogen, which causes the uterine lining to be sloughed off.
You can get pregnant whether you have withdrawal bleeding or not.
No. Withdrawal is NOT a safe method of birth control, and the bleeding needs to be checked out by your doctor.
Yes.
No.
It might temporarily, but then the withdrawal bleeding would probably start again when you stopped Prempro.
Yes.
Yes.
Yes.
Yes, withdrawal bleeding can be red, dark brown, or black when you're on hormonal birth control. Any of these counts as a withdrawal bleed.
When taking birth control pills the bleeding you get each month is withdrawal bleeding and not a "regular" period that comes on its own. So when you miss a few pills the withdrawal from them starts up the bleeding. The steady hormones in the pill keep the uterine lining thin. When you skip the pill for a few days, the pill hormone levels go way down (it takes the body about 24 hrs to eliminate the hormones in one pill). This withdrawal of pill hormones destabilizes the uterine lining and you get spotting/bleeding [thus, the name: withdrawal bleeding].
If you take out NuvaRing early, you may or may not have bleeding. This bleeding is withdrawal bleeding, not a menstrual period.
When you're taking the birth control pill, you don't have a menstrual period. Instead, you have withdrawal bleeding. Menstrual periods are vaginal bleeding the follows ovulation by 14 days. Withdrawal bleeding is vaginal bleeding brought on by sudden cessation of hormone ingestion. Whether you have unscheduled bleeding from missing a pill or scheduled bleeding during your placebo week, neither is called a menstrual period.