Emergency Contraception and Menstrual Cycle Changes

Emergency contraceptive pill

If your period started on April 1 and ended on April 5, and you had unprotected intercourse on April 6 followed by taking emergency contraception within four hours, the bleeding you experienced on April 11, which resembled a menstrual period but was heavier, could be a side effect of the emergency contraceptive.

Typically, the next menstrual cycle can be affected by the use of emergency contraception, and it may not follow the usual schedule.
Therefore, you should consider May 1 as the expected date for your next period, but it's also possible that your cycle may be irregular due to the emergency contraception.
Since it is now May 8 and you have not yet had your period, it would be advisable to take a pregnancy test if your period does not arrive soon.

Miss Chen, 20~29 year old female. Ask Date: 2016/05/08

Dr. Cao Guotao reply Obstetrics and Gynecology

Hello, emergency contraceptive pills can sometimes cause irregular menstruation.
For your next period, you should consider May 11 as the reference date.
If your period does not arrive within a week after it is due, it is advisable to consult a gynecologist.
Wishing you good health.

Reply Date: 2016/05/08

More Info

Emergency contraception (EC) is a method used to prevent pregnancy after unprotected sexual intercourse or contraceptive failure. It is most effective when taken as soon as possible after the event, ideally within 72 hours, but some forms can be taken up to 5 days later. The most common types of emergency contraception are hormonal pills, such as levonorgestrel (Plan B) and ulipristal acetate (ella), and the copper intrauterine device (IUD).

In your case, you took emergency contraception shortly after unprotected intercourse on April 6, following your menstrual period that began on April 1 and ended on April 5. It is not uncommon for emergency contraception to cause changes in your menstrual cycle. This can include earlier or later onset of your next period, as well as changes in flow and duration.
The bleeding you experienced on April 11, which you described as being similar to a menstrual period but heavier, could be a side effect of the emergency contraception. Hormonal fluctuations caused by the medication can lead to what is known as "withdrawal bleeding," which may occur before your next expected period. This bleeding can sometimes be mistaken for a regular menstrual period.

Regarding your question about when to expect your next period, it can be a bit tricky. If the bleeding on April 11 was indeed a withdrawal bleed due to the emergency contraception, it may not count as your regular menstrual period. In typical circumstances, if your menstrual cycle is regular, you would expect your next period approximately 28 days after the start of your last period (April 1), which would be around April 29. However, since you experienced bleeding on April 11, it may alter your cycle.

Given that today is May 8 and you have not yet had your next period, it is advisable to wait a few more days. If your period does not arrive by May 11, you should consider taking a home pregnancy test to rule out pregnancy. If the test is negative and your period still does not come, it may be wise to consult with a healthcare provider for further evaluation.

In summary, the bleeding you experienced after taking emergency contraception could be a side effect of the medication, and it may not indicate the start of your regular menstrual cycle. Monitor your symptoms, and if your period does not arrive within a week or two, seek medical advice. Remember that hormonal contraceptives can cause variations in menstrual cycles, and it is essential to keep track of any significant changes.

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