Does Ella Cause A Late Period?

In our latest question and answer, the pharmacist discusses how taking Ella, the emergency contraceptive, can cause changes to your period.


On July 4 I had sex and it was one day before ovulation starts. On July 5, I took Ella. Today, July 22, should be the first day of my period however there is a small amount of blood and like clots that are very dark brown. Could it be implantation or from the pill?

Asked by Becs On Jul 22, 2018

Answered by
Medical Content Reviewed By PharmacistAnswers Staff

On Jul 24, 2018

Ella (Ulipristal) is an emergency contraceptive that is taken to prevent pregnancy when someone has unprotected intercourse. It works by postponing ovulation.

According to the drug manufacturer, it is considered normal if your period is a couple of days late. However, if you are late by 7 days or more, have vomiting or nausea, have an unusually light or heavy period, breast tenderness or stomach pain, you should take a pregnancy test since there is a chance you may be pregnant. In other words, give your period a couple of extra days to come, but if it is not normal by 7 days after it should have normally come, you will need to take a pregnancy test to rule out the chance you are pregnant.

If you don't get your period, it doesn't necessarily mean you are pregnant. The prescribing information for the drug reports that 19% of individuals taking Ella reported having their period late by 7 or more days. A pregnancy test is to simply rule out the chance you may be pregnant.

Below is some additional information on taking Ella.

Important Information About Ella

Ella prevents pregnancy in approximately 98 out of 100 women who take it according to the manufacturer.  Some important information about taking Ella includes:

  • The tablet  should be taken as soon as possible after unintended, unprotected sex up to 5 days or 120 hours after.
  • The tablet can be taken anytime in a menstrual cycle.
  • It is important that after taking the tablet, you use a condom every time you have intercourse until your period comes.
  • Patients that should NOT take Ella include severe asthmatics, patients with severe liver disease or patients that have symptoms of pregnancy.
  • Ella does not protect against sexually transmitted diseases

Patients should read the full patient package pamphlet for more information. Some common side effects when taking Ella include:

  • Nausea or vomiting
  • Stomach pain
  • Painful period or pelvic pain
  • Breast tenderness
  • Headache
  • Dizziness
  • Mood changes
  • Fatigue
  • Back or muscle pain

Ella is a good option for emergency contraception for patients who have unprotected intercourse and are concerned about pregnancy. It is important when using any emergency contraceptive, like Ella , patients are aware of the correct way to take the drug, how it effects their period and when they should test for pregnancy if their period is late. Reading the accompanying patient information pamphlet can answer many of these questions. For further clarification, pharmacists can assist patients with their questions or concerns. 

About the Pharmacist

Ms. Jennifer Hauder RPh

Jennifer Hauder is a registered pharmacist in the state of Illinois. She has over 10 years experience as a pharmacist in the retail and pharmacy benefit managers (PBM) settings. She became a pharmacist due to her interest in healthcare and the opportunity to help others with their healthcare needs. When not working, she enjoys spending time with her husband, three children and two black labs Lucky and Charms.

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