Ask Ella: When to take a pregnancy test after the morning after pill

Waiting after taking emergency contraception can feel like staring at a clock that won’t budge. The big question is when to take a pregnancy test. If you test too early, you could get a false negative and only find out when you’re much further along in your pregnancy. Here’s a quick guide to the seven and 21-day rules, and as well as how ellaOne® might affect your period.

Pregnancy tests work by measuring the human Chorionic Gonadotropin (hCG) hormone, which your body only starts making once you become pregnant. It takes a while for the hormone to show up in your urine at a level your home pregnancy test can detect.

Does ellaOne® affect your period?

Emergency contraceptive pills, including ellaOne®, work by delaying ovulation. This temporary  shift in your cycle often causes your period to arrive slightly early, slightly late, or with a  different flow than usual. A late period doesn’t automatically mean the morning after pill failed.

You should always take a pregnancy test after the morning after pill if you are worried.  However, to get the most reliable result, follow one of the two rules below:  

The period rule: test if your period is more than seven  days late 

Your next period is the most reliable sign that the pill has worked. If your period is more than  seven days late from the date you originally expected it, you must take a test. This delay is  often due to the pill shifting your cycle, and a test will give you certainty.  

The 21-Day Rule: Test 21 days after unprotected sex 

If it’s been 21 days or more since you had unprotected sex, take a test. This 21-day period  allows your body enough time to produce detectable levels of the hCG pregnancy hormone.

Once you’ve waited the correct amount of time, your result should be accurate. 

What does a negative result mean? 

A negative test result means you are very unlikely to be pregnant. If your period still hasn’t arrived a week after the negative test, you should repeat it or contact a doctor. 

What if I get a positive pregnancy test after the morning after pill? 

If the test is positive, that means that you are pregnant. Contact your GP or a local sexual health clinic immediately to discuss your options, which generally include: 

• Continuing the pregnancy: arranging for ante-natal care and support 
• Adoption: exploring support services and procedures for placing the child for adoption
• Termination: Discussing legal and clinical options for ending the pregnancy

Once you have an accurate result from your pregnancy test, the next steps are really important for both your health and peace of mind. Remember, medical professionals are there to support you through any outcome. 

When to get urgent help 

While emergency contraception is highly effective, it does not protect against ectopic pregnancy (a serious condition where the pregnancy develops outside the uterus). Get help immediately if you experience any of the following symptoms: 

• Severe, persistent abdominal pain, especially pain concentrated on one side
• Unexplained shoulder tip pain (a common sign of internal bleeding from an ectopic pregnancy) 
• Unusually heavy vaginal bleeding or spotting combined with pain
•  Symptoms of shock (dizziness, fainting, paleness)

Waiting to take a pregnancy test after the morning after pill can feel stressful, but getting the timing right will clear your mind. Wait 21 days after unprotected sex, or test if your period is more than seven days late. A slight delay can be normal, since the pill can shift your cycle. Whatever the result, you can always speak to your GP who will support you on next steps.

1. Can the morning after pill give a false positive?

No, ulipristal acetate, which is the active ingredient in ellaOne®, cannot directly cause a false positive result on a home pregnancy test. Pregnancy tests detect the hCG hormone, which is unrelated to the medication in the morning after pill. 

 2. What if I get a faint line on the test?

Faint lines indicate a positive result. Even if your result is a faint positive, you should contact a doctor or clinic immediately for a blood test and confirmation. 

3. Is the pill still effective if I miss my window to test?

Yes. The pill works by preventing ovulation, and the test simply shows the outcome. Missing the testing window only delays knowing the result, it does not reduce the pill’s effectiveness.

References: 

1) https://www.nhs.uk/pregnancy/trying-for-a-baby/doing-a-pregnancy-test/ 2) https://www.nhs.uk/conditions/ectopic-pregnancy/

1) https://www.nhs.uk/pregnancy/trying-for-a-baby/doing-a-pregnancy-test/ 2) https://www.nhs.uk/conditions/ectopic-pregnancy/