Period not starting after taking PlanB

Patient: I am on the pill but had unprotected sex. I was still worried so I took PlanB but later realized that I was not ovulating. I was supposed to get my period 3 days ago but haven’t gotten it yet. Did the PlanB affect my period?

Doctor: When you are on birth control pills, you are protected against pregnancy unless you miss pills and taking them irregula rly. You do not need any other form of additional contraception in such a case. The primary action by which these pills act is by preventing ovulation from taking place.However if you are not on regular birth control, then taking an emergency contraceptive pill was a good idea. You are correct in thinking that your periods may have been delayed due to the morning after pill as that is indeed one of its side effects. However just to be sure, if you do not get your periods by another week, it would be advisable to take a pregnancy test at home or at a clinic. Though the morning after pills are highly effective in preventing an unwanted pregnancy there is always a chance of a failure. To be better protected, I would recommend you follow a combined birth control pill regimen regularly.