Many women assume Plan B is harmless because it is available over the counter. It may seem like a simple solution to prevent pregnancy after unprotected sex, but it is not as simple of a solution as you may think.
Plan B Was Not Designed for Regular Use
Plan B contains levonorgestrel, a synthetic hormone that was designed to be taken as a last-resort option for pregnancy prevention in the event of unprotected sex or contraceptive failure. It works by thickening the mucus from the cervix to prevent the sperm from traveling up the cervix and inhibits ovulation by altering the lining of the uterus, that is, the endometrium.
“Timing of the use is very important in regards to effectiveness,” says Dr. Snider, a physician serving on Two Lines Pregnancy Clinic’s Board of Directors and Medical Advisory Group. “If ovulation has already occurred, the medication is not considered effective in preventing pregnancy.”
Plan B is not a guarantee against pregnancy.
What Happens If Plan B is Taken More Than Once?
While women can technically take Plan B more than once, repeated use exposes the body to frequent, high doses of synthetic hormones and can cause the following negative side effects:
- Irregular bleeding
- Spotting between periods
- Earlier or later menstrual cycles
- Nausea
- Fatigue
- Breast tenderness
- Headaches
- Mood changes
Many women report that after taking Plan B multiple times, their cycle feels unpredictable. Periods may arrive earlier than expected, later than expected, or look very different from a typical cycle.
Questions Remain About Its Effects
Plan B is generally understood to work by delaying or preventing ovulation, which helps prevent fertilization from occurring in the first place. However, some medical professionals have raised questions about whether the medication could have additional effects if ovulation or fertilization has already occurred before the drug takes effect.
Dr. Snider explains, “There are concerns that the medication might change the lining of the uterus to make the lining less receptive to implantation, or that it might have an effect on a fertilized egg.”
The concern is not that Plan B routinely works after fertilization, but rather whether there are situations in which fertilization could occur despite taking the medication. In those cases, some researchers and physicians have questioned whether changes in the uterine lining could affect implantation or the development of a newly fertilized egg. While Plan B is commonly described as preventing ovulation, debate continues among some medical professionals regarding whether its effects may extend beyond that mechanism.
How Do You Know If Plan B Worked?
If you have taken Plan B after unprotected sex to prevent pregnancy, the only way to know whether it was effective is to wait. However, because Plan B can affect the timing of your menstrual cycle, it may be difficult to know whether a late period is caused by the medication or by pregnancy.
Women who take Plan B and get pregnant anyway are at a higher risk of having an ectopic pregnancy, a potentially life-threatening condition in which a fertilized egg implants outside the uterus. The only way to be able to determine this with accuracy is through a sonogram. If you’ve taken Plan B and are experiencing a late period, unusual symptoms, or ongoing uncertainty, Dr. Snider recommends seeking care from a medical provider immediately.
You Deserve Clear Answers
Two Lines Pregnancy Clinic is here for you.
We offer no-cost pregnancy testing and limited ultrasounds in a confidential, compassionate environment. Our goal is to help you understand what’s happening in your body so you can make informed decisions about your health.
You don’t have to navigate uncertainty alone.
We’re with you.