Will You Get Your Period After Taking Ella?

In our latest question and answer, the pharmacist discusses whether or not taking ella can cause a delay in getting your period.

Jul 09, 2018

Khaoula asked

I had unprotected sex during my ovulation days, then I took an Ella tablet two days after. Now, my period is late for two days. I have no pregnancy symptoms. Should I take a test? Can I get pregnant?


Ella, an emergency contraceptive, can cause changes to your usual menstrual cycle, which includes experiencing early or late menses. Per the prescribing information for Ella:

"After ella intake, menses sometimes occur earlier or later than expected by a few days. In clinical trials, cycle length was increased by a mean of 2.5 days but returned to normal in the subsequent cycle. Seven percent of subjects reported menses occurring more than 7 days earlier than expected, and 19% reported a delay of more than 7 days. If there is a delay in the onset of expected menses beyond 1 week, rule out pregnancy. Nine percent of women studied reported intermenstrual bleeding after use of ella."

So, almost 20% of individuals who take ella will have their menses delayed by more than 7 days. As per the prescribing information, a pregnancy test should be taken if you are more than 7 days late getting your period. A late period (or not getting it at all) doesn't mean you are pregnant, but it should just should be ruled out.

Additional Information About Ella

Ella works differently than other emergency contraceptives, such as Plan B. While Plan B delivers a high dose of the progestin levonorgestrel, ella binds to the progesterone receptor, and prevents progesterone from binding. This works to delay or inhibit ovulation (release of an egg).

Ella has the greatest efficacy if taken within 5 days of unprotected sex. While it does reduce the chances of becoming pregnant, pregnancy is still possible. Therefore, if your menses is more than 7 days late, it is important to take a pregnancy test.

There are two important points to know about ella after you have taken it:

  • For the rest of your menstrual cycle, you should use an alternative form of contraception (e.g. condoms) if you have sexual intercourse. You can resume your normal method of birth control (e.g. pills) your next cycle.
  • Taking birth control pills with ella could reduce contraceptive efficacy of ella. After using ella, you need to wait at least 5 days before you continue taking your birth control pills. Alternative contraceptives (e.g. condoms) should be used instead. In addition, the alternative form of contraception should be used until the next menstrual period.


  • Ella may cause changes to your menstrual cycle, including causing it to occur earlier than usual or later than usual.
  • If your menses is more than 7 days later than expected, it is important to take a pregnancy test to rule out the chance of pregnancy.

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