You will know that ella has worked when you get your next period. Your period may come later or earlier than your usual cycle. However, if your period is delayed beyond one week of your usual cycle, it is best to take a pregnancy test to confirm whether or not ella has worked.
Possible short-term side effects include: headache, nausea, stomach pain, irregular spotting or bleeding, menstrual pain or cramps, tiredness or dizziness.
If you are experiencing severe abdominal pain at any point after taking ella, seek medical treatment right away as this could indicate an ectopic or tubal pregnancy.
For more information about ella you can also check out the ella website.