If you’re not planning on becoming pregnant, the morning-after pill, also known as Plan B, can be a lifesaver. According to Planned Parenthood, taking it within three days of unprotected sex can reduce your chances of pregnancy by 89 percent. This can provide a huge relief if you forgot to take your regular birth control pill, your contraception failed (like a broken condom), or you were unable to use your usual birth control method for any reason. However, it’s important to note that there can be side effects.
For example, if you’ve taken Plan B in the past and experienced changes in your menstrual cycle, you’re not alone. While Plan B is completely safe, one of its main temporary side effects is a disruption in your menstrual cycle. It is common for many people to find their period become unpredictable or irregular for a few weeks after taking the pill. If this unpredictability persists for months, it could be a sign of an underlying health condition.
The morning-after pill should be taken as soon as possible after unprotected sex for maximum effectiveness, as waiting too long can reduce its efficacy. It is also not a replacement for regular birth control methods.
After taking Plan B, it is normal for your next period to be affected. Dr. Mary Shorey, an OB/GYN at Johns Hopkins Bayview Medical Center, explains that Plan B works by delaying ovulation, which can impact the timing of your period. It can cause your period to be delayed by a few days, come earlier than expected, or result in lighter or heavier bleeding than usual. Spotting or irregular bleeding is also common in the week or month following emergency contraception use.
While the side effects of Plan B are short-lived and typically subside within a few weeks, there are other possible minor side effects to be aware of, like headaches, upset stomach, lightheadedness, tender breasts, and fatigue. If you experience nausea and vomiting within two hours of taking the pill, it may not be effective.
In rare cases, Plan B spotting could be mistaken for implantation bleeding. To rule out pregnancy, Dr. Sonya Brar, an OB/GYN at Mount Sinai, recommends taking a pregnancy test if your period is delayed for more than three weeks after taking Plan B. If your cycle remains irregular for months, it could be a sign of an underlying health condition, in which case you should consult your doctor.
In general, Plan B should not disrupt your menstrual cycle for months. Most people will see their period return to normal within one week of the expected time. If you experience persistent irregular bleeding or lower abdominal pain, it’s important to seek medical advice to rule out any potential complications.
While it’s safe to take Plan B multiple times if needed, it should not be used as a regular form of birth control. It may be less effective for certain groups, such as individuals with obesity. Consult with your doctor about prescribing Plan B and discussing long-term birth control options that are more reliable and effective.
