Top things to know about your period on the pill:
Your “period” on the contraceptive pill is actually called withdrawal bleeding. It happens when the levels of hormones in your pills drop.
Withdrawal bleeding is usually lighter and slightly different than the period you had before taking the pill
Some people experience only very light bleeding or don’t bleed at all during placebo pill days
Your bleeding on the pill is likely to change over time
Do you get a period on when you’re on the combined hormonal contraceptive pill*? On the days you take no pills or take the pills in your pack with no (or few) hormones, you may experience bleeding. This bleeding is different than a period if you weren't taking the contraceptive pill—and you may have times when you bleed very little or not at all.
*This article refers to the use of combined hormonal contraceptive pills, which contain both estrogen and progestin (the most common type). Bleeding patterns will be different for people taking the progestin-only minipill.
Do I get a “real” period on the contraceptive pill?
Nope. The bleeding you get when you’re on the pill is not the same as a menstrual period.
Your period on the pill is technically called withdrawal bleeding, referring to the withdrawal of hormones in your pill, and in your body. The drop in hormone levels causes the lining of your uterus (the endometrium) to shed (1). This bleeding may be slightly different than the period you had before taking the pill. It also may change over time while taking the pill.
What exactly is happening my body? Do I ovulate on the contraceptive pill?
No. If you take your pill consistently and correctly, you shouldn’t ovulate. This is the primary way the pill prevents pregnancy. In a usual (no-pill) cycle, the body’s natural reproductive hormones fluctuate up and down, taking your body through a process of preparing an egg for release, releasing that egg, and preparing your uterus to accept a potentially fertilized egg.
The hormones in the contraceptive pill stop and prevent your ovaries from preparing and releasing eggs. They stop the usual hormonal “cycling”, including ovulation, the typical growth of the endometrium, and the natural period.
Why is my bleeding different on the contraceptive pill?
The contraceptive pill prevents the lining of your uterus (your endometrium) from growing thicker, as it would in a typical menstrual cycle (2-3). It also prevents ovulation and the typical cycling of reproductive hormones. When you have withdrawal bleeding, the bleeding tends to be lighter than normal menstrual bleeding.
It’s also possible to have no withdrawal bleeding or only spotting during the days you take inactive pills (or no pills). This is more common for people taking higher doses of estrogen, or a pill with a shorter (or no) hormone-free interval (most pill packs have seven placebo pills but check your pack’s box and info sheet if you’re not sure or talk to your healthcare provider.) (4-5).
What’s “normal” bleeding while on the contraceptive pill?
Your body’s response to your pill will depend on the type of pill you take, and your own body’s hormones. If you’re taking a typical 21/7 monophasic pill (where all active pills have the same amount of hormones—check your pack), bleeding may start on day two or three of your placebo week and last 3-5 days on average. A few people may have only one day of bleeding mid-week, and others may have bleeding that extends into their next pill pack. Up to 1 in 10 have no withdrawal bleeding at all (not including spotting) (5).
Bleeding on the contraceptive pill is also likely to change over time. In people using the 24/4 day pill (24 active hormone pills & four placebo pills), about 1-2 in 10 had no significant withdrawal bleeding by the 6th pill pack (4). Bleeding also tended to decrease over time.
No bleeding can also signal a pregnancy. Take a pregnancy test if you’re unsure, especially if you haven’t taken your pills correctly in the previous pack.
Unexpected bleeding on the contraceptive pill
Spotting can happen outside of your usual withdrawal bleed time. This is called breakthrough bleeding. It doesn’t mean your pill isn’t working, but it can be frustrating to deal with (2). Up to 1 in 5 people experience breakthrough bleeding when first taking the contraceptive pill (6). It is not usually a cause for concern and will often stop after a few weeks or months (7). Others will need to try a different pill brand, with different levels of hormones. Many experts recommend choosing a pill with the lowest dose of estrogen (ethinylestradiol/EE), and only changing to a higher dose if breakthrough bleeding is a persistent problem (7).
Spotting can also be caused by missed pills, as the drop in hormone levels can cause a small amount of withdrawal bleeding.
What kind of bleeding is considered normal while on the contraceptive pill?
Unexpected spotting for the first few months while taking a new pill (talk to your healthcare provider if it’s still happening after 3 months)
Withdrawal bleeding that is lighter, or shorter than your period before you were taking the pill
Withdrawal bleeding that changes slightly over time while on the pill
Having little or no bleeding during your placebo week after taking your pills correctly
Article was originally published on September 13, 2017