Emergency Contraception: Effects and Concerns After Use

Post-coital contraceptive issues

On April 23, my girlfriend and I had sexual intercourse.
It was her first time, and we had sex around 3 or 4 AM without using a condom.
I did not ejaculate inside her.
We had sex again at around 8 AM, again without a condom and without ejaculation.
I understand that even without ejaculation, there can be some sperm present, such as in pre-ejaculatory fluid.
Later that morning, around 10 or 11 AM, she took an emergency contraceptive pill.

Her menstrual cycle usually starts around the 30th of each month and lasts about 4 to 6 days.
However, as of April 30, her period had not started, and today is May 2.
Does the emergency contraceptive pill affect the timing of her period, and how long can it be delayed? What is the likelihood of pregnancy in this situation?
After taking the emergency contraceptive pill on the morning of April 23, she felt a bit tired and wanted to sleep.
From April 25 to April 29, she mentioned feeling very sleepy at school.
Could this be a side effect of the emergency contraceptive pill? Recently, she has felt better, but she still experiences some sleepiness.
Are the side effects of the pill really that significant?
If her period does not come, what should we do? Is it normal for her to be late after taking the emergency contraceptive pill?

Xiao Zhu, 10~19 year old female. Ask Date: 2016/05/03

Dr. Zhang Kunmin reply Obstetrics and Gynecology

Hello, the effectiveness of emergency contraception taken within 72 hours after intercourse is about 97%, but it is not 100%, with a failure rate of approximately 3%.
The effects of emergency contraception on menstruation can vary and may not necessarily result in an earlier or later period.
Additionally, early pregnancy may not present specific symptoms, and subjective symptoms cannot be used to make a judgment.
It is recommended to take a pregnancy test if your period is more than a week late.
Thank you! Wishing you safety and health.
Dr.
Zhang

Reply Date: 2016/05/03

More Info

Emergency contraception (EC) is a critical option for individuals who have had unprotected intercourse and wish to prevent an unintended pregnancy. In your situation, your girlfriend took an emergency contraceptive pill (ECP) shortly after the sexual encounter, which is a responsible step to mitigate the risk of pregnancy.
ECPs, such as those containing levonorgestrel or ulipristal acetate, work primarily by delaying ovulation. If taken within 72 hours of unprotected intercourse, they can significantly reduce the chance of pregnancy. However, the effectiveness of these pills can vary based on several factors, including the timing of ovulation in the menstrual cycle and how soon after intercourse the pill is taken.

Regarding your specific questions:
1. Menstrual Cycle Changes: It is common for ECPs to cause changes in the menstrual cycle. They can lead to a delay in the onset of menstruation, and this delay can vary from a few days to a week or more. In some cases, women may experience their period earlier than expected. Given that your girlfriend's average cycle starts around the 30th of each month, a delay until May 2nd is not unusual after taking the ECP. If her period does not arrive within a week of the expected date, it is advisable for her to take a pregnancy test to confirm whether she is pregnant.

2. Side Effects: The side effects you mentioned, such as fatigue and drowsiness, can indeed be associated with the use of emergency contraception. Other common side effects include nausea, headache, breast tenderness, and changes in menstrual bleeding. These side effects are typically temporary and should resolve within a few days. If your girlfriend continues to feel excessively fatigued or experiences other concerning symptoms, it would be wise for her to consult a healthcare provider.

3. Pregnancy Risk: The likelihood of pregnancy after taking an ECP is significantly reduced, but it is not eliminated entirely. Factors such as the timing of the menstrual cycle and whether ovulation has already occurred play a crucial role. If your girlfriend took the ECP within a few hours after unprotected intercourse, the chances of pregnancy are lower, but if ovulation was imminent, there is still a risk.

4. What to Do If Menstruation Is Delayed: If her period does not arrive within a week of the expected date, she should take a home pregnancy test. These tests are generally reliable and can provide peace of mind. If the test is positive, she should seek medical advice to discuss her options. If the test is negative and her period still does not come, it may be beneficial for her to consult a healthcare provider to rule out any other underlying issues.

In summary, while emergency contraception is effective, it can cause temporary side effects and may alter the menstrual cycle. Monitoring her symptoms and taking a pregnancy test if her period is significantly delayed will help in managing the situation. If there are any persistent or severe symptoms, seeking medical advice is always the best course of action.

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