Understanding Withdrawal Bleeding on Birth Control

Withdrawal bleeding occurs when you are on hormonal birth control and you bleed – whether this is your ‘period’ or bleeding between ‘periods’.

You can never get a real period when you are on hormonal birth control, because you are not ovulating. To set off the hormonal cascade required to build up your endometrial lining, then not get pregnant, you need to ovulate. No ovulation, no period.

You get withdrawal bleeding when you come off hormone therapy, the pill, contraceptive rings, patches, implants and injections.

How is breakthrough bleeding different to withdrawal bleeding?

Withdrawal bleeding is different from breakthrough bleeding. When you are on hormone therapy or hormonal birth control, breakthrough bleeding can appear after running pill packets/rings/patches together or being on one type of hormone therapy for a while.

Breakthrough bleeding may appear as spotting, or a period that never quite fully appears. Breakthrough bleeding tends to stabilise the longer you are on birth control.

The trend in birth control these days is to have the lowest possible dose to prevent pregnancy, but this leads to some instability of the endometrial lining, which is very hormone-dependent.

Low doses can lead to breakthrough bleeding. Breakthrough bleeding is different to withdrawal bleeding, but both usually happen when you are on hormonal birth control.

So why do I bleed during my 7-day break from my birth control?

The sole reason that you take a 7-day break from your birth control is so you ‘don’t feel weird about not having a period’. That’s right. Doctors decided that women would find not getting a period to be disconcerting, so they decided we should take a 7-day break for a bleed to reassure us that we were normal or not pregnant, even though the opposite is true.

There is nothing natural about being on hormonal birth control because in fact your body is, in a way, tricked into thinking it’s already pregnant! The cause of the bleeding is a rapid drop in the synthetic hormones the birth control contains.

Why the 7-day break can end you up pregnant

Birth control for 25 per cent of the time – which is what the 21 days on and 7 days off effectively is – contributes to the pill’s failure rate, and is not required at all.

You can safely run your pills or rings together and get no period, until eventually you’ll start breakthrough bleeding. If you start your new cycle of pills late, you are risking ovulation, because you have already gone seven days without any hormonal intervention, and your body will start to take back over.

If you are, say, sick at the end of the 7-day break, and have vomiting or diarrhoea, the pill may not be absorbed, and thus your body may not respond and voila – you may ovulate and get pregnant. This may also include the final pills in the 21-day pack, effectively elongating your break without pills.

Running your pills together – tricycling or bicycling

Many women run three packets of pills together, taking a break four times a year instead of 12 times per year. This is called tricycling. Same applies for running two packs together – bicycling.

Women who get headaches or migraines when they stop taking pills, or women with endometriosis, may benefit from tricycling. This reduces the opportunities for symptoms associated with changes in hormone levels or bleeding.

Anyone on a phasic pill where there are a few different types of active pills may experience breakthrough bleeding (but contraception remains secure) when running packets together.