Effectiveness of Emergency Contraceptive Pills and Menstrual Cycle Impact

Emergency contraceptive pill

Hello, doctor.
I had unprotected sexual intercourse on the afternoon of July 4th and took emergency contraception the next day at noon (within 24 hours).
Is this effective for preventing pregnancy? Will my menstrual period be early or delayed? My last menstrual period started on June 22nd.

lin, 20~29 year old female. Ask Date: 2015/07/06

Dr. Lü Lizheng reply Obstetrics and Gynecology

1.
Emergency contraception can reduce the likelihood of pregnancy by up to 80%.
2.
There is a higher possibility of an earlier menstrual period.
Sincerely, Dr.
Li-Cheng Lu, Taoyuan Hospital.

Reply Date: 2015/07/06

More Info

Emergency contraceptive pills (ECPs), commonly referred to as "morning-after pills," are designed to prevent pregnancy after unprotected sexual intercourse. The effectiveness of ECPs, such as levonorgestrel (Plan B One-Step) or ulipristal acetate (Ella), is highest when taken as soon as possible after the incident, ideally within 72 hours for levonorgestrel and up to 120 hours for ulipristal acetate. Since you mentioned taking the emergency contraceptive pill within 24 hours after unprotected intercourse, you have maximized your chances of preventing pregnancy. Studies indicate that ECPs can reduce the risk of pregnancy by up to 89% when taken within the recommended time frame.

Regarding the impact on your menstrual cycle, it is important to note that ECPs can cause some temporary changes in your menstrual cycle. Some women may experience their next period earlier or later than expected, and the flow may be lighter or heavier than usual. In your case, since your last menstrual period started on June 22, you would typically expect your next period around July 22, assuming a regular 28-day cycle. However, after taking the emergency contraceptive pill, it is not uncommon for your period to arrive a few days earlier or later than this expected date.

If your period is delayed by more than a week after the expected date, it is advisable to take a pregnancy test to confirm whether or not you are pregnant. Additionally, if you experience any unusual symptoms or have concerns about your menstrual cycle or the effects of the emergency contraceptive pill, it is always best to consult with a healthcare provider for personalized advice and guidance.

In summary, taking the emergency contraceptive pill within 24 hours of unprotected intercourse is an effective method to prevent pregnancy. While it may cause some temporary changes to your menstrual cycle, these are generally not a cause for concern. If you have any further questions or experience significant changes in your cycle, do not hesitate to reach out to a healthcare professional for support.

Similar Q&A

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;...

Understanding the Impact of Emergency Contraception on Your Menstrual Cycle

Hello doctor, I had unprotected intercourse with my boyfriend on January 23, and I took the emergency contraceptive pill the next morning on January 24, which is effective for 72 hours. However, I am confused because my period started on January 17 and ended on January 22. After ...

Dr. Zhang Kunmin reply Obstetrics and Gynecology
Hello, the factors affecting the menstrual cycle or intermenstrual bleeding are numerous, including age, environment, lifestyle, stress, emotional instability, weight changes, medications, emergency contraceptive pills, diet, uterine or cervical lesions, infections, pregnancy, an...

Impact of Emergency Contraceptive Pills on Menstrual Cycle Timing

If you take the emergency contraceptive pill and experience bleeding for 7 days after 5 days, will your regular menstrual period still occur? Will it be early or delayed?

Dr. Cai Yonglong reply Obstetrics and Gynecology
Dear Dr. Li Shurong of the Department of Obstetrics and Gynecology at Tainan Hospital, Ministry of Health and Welfare, The emergency contraceptive pill works by utilizing high doses of progestin to achieve contraceptive effects. However, there are many types of medications avail...

Impact of Emergency Contraceptive Pills on Menstrual Cycle and Fertility

I would like to inquire about my situation. I started taking emergency contraceptive pills from May to June, taking them more than five times. In July, my menstrual period was very light, only enough to fill a panty liner, but it lasted for about 5 to 6 days. After that, I experi...

Dr. Zhang Kunmin reply Obstetrics and Gynecology
Taking any emergency contraceptive pill may affect the timing, duration, and flow of menstruation, but this varies by individual. Generally, high-dose progestin formulations are less likely to disrupt the menstrual cycle. Regular use is not recommended, and it is especially disco...