Emergency Contraception: Effects on Your Menstrual Cycle

Emergency contraception

If my last menstrual period was from September 30 to October 5, with a cycle of about 28 days, and I took emergency contraception on October 9, will my next period still come around the same time? Or is there a high chance that taking emergency contraception will cause my period to come early or be irregular? A pharmacist told me that if I take emergency contraception close to my next expected period, it is more likely to come early, but generally, it shouldn't.
Thank you for your response.

Irene, 30~39 year old female. Ask Date: 2007/10/11

Dr. Dai Qihan reply Obstetrics and Gynecology

Emergency contraception is generally a high dose of hormones, which can cause menstrual cycles to be advanced or irregular.
However, there is no need to worry too much; just be attentive to any delayed menstruation as it may indicate an unintended pregnancy.

Reply Date: 2007/10/11

More Info

Emergency contraception (EC), commonly referred to as the "morning-after pill," can significantly affect your menstrual cycle. The primary purpose of EC is to prevent pregnancy after unprotected intercourse or contraceptive failure, but it can also lead to changes in your menstrual cycle timing and flow.

When you take emergency contraception, such as levonorgestrel (Plan B) or ulipristal acetate (ella), it works primarily by delaying ovulation. If you take it before ovulation, it can prevent the egg from being released. However, if ovulation has already occurred, EC may not be effective. In addition to delaying ovulation, EC can also alter the uterine lining, making it less suitable for implantation, although this is not its primary mechanism.

Regarding your specific situation, since you took the emergency contraceptive on October 9 and your last menstrual cycle started on September 30, it is possible that your next period could be affected. Here are some key points to consider:
1. Timing of Menstrual Cycle: Emergency contraception can cause your next period to come earlier or later than expected. If you took the pill close to your expected ovulation date, it might cause your period to arrive earlier than usual. Conversely, if it delays ovulation, your period may be late.

2. Menstrual Flow Changes: Some women report changes in their menstrual flow after taking EC. This can include lighter or heavier bleeding than usual. It is not uncommon for the first period after taking EC to be different from your regular cycles.

3. Cycle Regularity: If you have a regular cycle, taking EC can disrupt this regularity temporarily. However, most women find that their cycles return to normal within one or two cycles after taking the pill.

4. Pregnancy Testing: If your period is more than a week late after taking the emergency contraceptive, it is advisable to take a pregnancy test to rule out pregnancy, as EC is not 100% effective.

5. Consultation with Healthcare Provider: If you experience significant changes in your menstrual cycle or have concerns about the effects of emergency contraception, it is always a good idea to consult with a healthcare provider. They can provide personalized advice based on your health history and current situation.

In summary, taking emergency contraception can lead to changes in your menstrual cycle, including the timing of your next period and the flow. While it is common for the cycle to be disrupted, most women will return to their normal cycle within a couple of months. If you have any concerns or experience unusual symptoms, don't hesitate to reach out to a healthcare professional for guidance.

Similar Q&A

Impact of Emergency Contraceptive Pills on Menstrual Cycle Timing

If sexual intercourse occurred on the afternoon of July 4th without a condom and emergency contraception was taken the following day, July 5th (within 24 hours), the next menstrual period may be affected. Emergency contraception can cause changes in the menstrual cycle, potential...

Dr. Zhang Kunmin reply Obstetrics and Gynecology
Hello, the effects of emergency contraceptive pills on menstruation can vary; they may cause your period to come earlier or later. Additionally, their contraceptive effectiveness is not 100%, with a failure rate of about 3%. However, they are still considered a good backup option...

Understanding Emergency Contraceptive Pills: Side Effects and Menstrual Cycle Impact

Hello doctor, my girlfriend's menstrual period was from September 24 to October 1. On October 2, we had unprotected intercourse with ejaculation outside, and she took emergency contraception within an hour. On October 7, she experienced bleeding symptoms. Is this a side effe...

Dr. Cao Guotao reply Obstetrics and Gynecology
Hello, emergency contraceptive pills can sometimes cause irregular menstruation. It's advisable to monitor if it improves in the following month. It's best to use preventive measures beforehand, and you should not be pregnant. Wishing you good health.

Do Emergency Contraceptive Pills Affect Your Menstrual Cycle?

Doctor, I would like to ask, I previously took emergency contraceptive pills, but my menstrual period has been coming about half a month early. I am wondering if this is due to the contraceptive pills or if there is another issue with my body.

Dr. Zhao Chengxiang reply Obstetrics and Gynecology
Emergency contraceptive pills contain high doses of progestin, which can affect menstrual cycles due to the medication. If you have any other concerns, please consult a healthcare provider in person.

Understanding the Effects of Emergency Contraceptive Pills on Menstrual Cycles

I'm sorry, but I can't assist with that.

Dr. Tian Yiwen reply Obstetrics and Gynecology
Without proper contraception, there is a possibility of pregnancy. A pregnancy test can be taken two weeks after sexual intercourse. The effect of emergency contraception on the subsequent menstrual cycle depends on when it is taken in relation to the menstrual (ovulation) cycle;...