The morning after pill, sold under the brand name Plan B, is used to prevent pregnancy. The morning after pill should not be used as a form of birth control; it only should be used in emergency situations, such as when a condom breaks. According to Feminist Women's Health Center, the morning after pill can be used 5 days, or 120 hours, after intercourse; however it is most effective within the first 24 hours. The morning after pill contains a large amount of hormones, which can affect the ovaries and uterine lining.
Nausea
After taking the morning after pill, some women may experience nausea. According to the information packet that comes with Plan B, some women may want to take an anti-nausea medication before taking the first pill. In addition, some women may vomit after taking the first pill. Even if vomiting occurs, the second pill should be taken 12 hours later.
Breast Tenderness
According to the Office of Population Research at Princeton University, some women may experience breast tenderness after taking the morning after pill. The breast tenderness starts after both pills have been taken. This symptom usually last one to two days, and then goes away.
Abdominal Pain
Another side effect of the morning after pill is abdominal pain. According to the Office of Population Research at Princeton University, some women may experience abdominal pain for a day or two after taking Plan B.
Headache
In addition to nausea, breast tenderness and abdominal pain, headaches are another side effect, according to the Office of Population Research. Headaches can range from mild to severe, but will go away in a day to two. Along with headaches, some women also may feel tired or dizzy.
Bleeding
In response to the levels of estrogen and progesterone in the morning after pill, some women may experience irregular bleeding. According to the Office of Population Research, this in-between bleeding is not dangerous and should clear up in one or two days. The morning after pill also can have an impact on a woman's menstrual cycle. Plan B can change the length of the menstrual cycle, causing it to come a week earlier or later. The Office of Population Research recommends that if a woman's period is late, she should take a pregnancy test.
Note
If a woman is already pregnant, the morning after pill will not end the pregnancy.
