Plan B and Ella® morning after pills: How they work, common side effects and when each expires

With the uncertainty surrounding the recent Supreme Court decision to overturn Roe v. Wade, many people with a uterus are purchasing extra doses of emergency contraceptive pills, also known as morning after pills.   

There are two types of emergency contraceptive pills: 

Plan B  

  • Available over the counter without a prescription 
  • Needs to be taken within 72 hours of unprotected sex 
  • Works by blocking ovulation with a high dose of progesterone 
  • Will only prevent pregnancy before ovulation has occurred  
  • Has a four-year shelf life 


  • Requires a prescription, which can be obtained by calling the University Health Center nurse line at 402.472.7477 
  • Needs to be taken within five days of unprotected sex 
  • Works by blocking your body’s use of progesterone, which either stops ovulation or prevents an egg from attaching in the uterus 
  • Will prevent pregnancy both before ovulation has occurred and a little later in the cycle after the luteinizing hormone surge (the change in hormones that initiates ovulation) 
  • Has a three-year shelf life 

The University Health Center offers both emergency contraception options at the pharmacy during business hours.  

If you need emergency contraceptive pills when the health center is closed, try After typing in your ZIP code, the website lists online stores that will ship the pills to your door.  

Plan B and Ella® side effects  

Both pills can delay your period and make bleeding come a little sooner than you expected. They both can cause nausea. If you experience heavier than normal bleeding, schedule an appointment with a University Health Center doctor by calling 402.472.5000.  

Can emergency contraceptive pills cause infertility or ectopic pregnancies? 

No, there’s no evidence that emergency contraceptive pills like Plan B and Ella® cause infertility. And no, they do not cause or increase the risk for an ectopic pregnancy. They actually decrease the risk for an ectopic pregnancy by preventing pregnancy in the first place.  

When to get help from a doctor 

Schedule an appointment with a University Health Center doctor if you: 

  • Experience bleeding that is soaking a pad every hour, lasting for two hours or longer 
  • Have trouble keeping the pills down or feeling nauseous. A doctor can prescribe anti-nausea medication to help  

If you experience severe abdominal pain, schedule an appointment with an OB-GYN or visit the nearest emergency room. This could be a sign of an ectopic pregnancy. 

If you have not had a period within three weeks of taking Plan B or ella®, take a pregnancy test. Learn about the pregnancy test options available through the health center 

Have questions about your reproductive health? 

If you would like to talk to a doctor about birth control or any other reproductive health topic, please call 402.472.5000 to schedule an appointment.