Hello, and I hope I can help you today.
First of all, I want to reassure you that unwanted 72 is over 90% effective in preventing
pregnancy if taken within 72 hours of unprotected sex.
Secondly, many women have some vaginal bleeding between three and seven days after taking emergency contraceptives. This is due to the drop in hormones after the unwanted 72 is out of her system. This is actually reassuring and a sign that the medication worked and she did not get pregnant.
Your girlfriends next real menstrual cycle may be delayed also, which is a common side effect of unwanted 72.
So, it is most likely that your girlfriends irregular period is just due to the unwanted 72. If you need further reassurance, modern
pregnancy tests are extremely accurate it and will become positive within 10 days to two weeks after an act of
unprotected intercourse. So if enough time has gone by, your girlfriend could perform a urine pregnancy test to make sure that she did not get pregnant. I hope that I was able to adequately answer your question at this time and that my advice was reassuring.
Best wishes,
Dr. Brown