How does the Plan B emergency contraception work?

Dear Ask The Doctor: Hi, i just want to know how the plan b pill works exactly. I took the pill 68 hours after having sexual intercourse and people tell me that i may have took it too late. But I am having some tightening in my abdominal area so I want to know if this means the pill is working or if i took the pill too late? I had intercourse may 12 at 9 am in the morning and i took the pill on may 15 around 4 am in the morning..

Dear Kimone: Plan B is an emergency oral contraceptive plan. It basically is an Oral contraceptive pill and thus works in the same way by preventing ovulation and/or thickening the cervical mucous and thus helps in preventing pregnancy. Typically it should be taken immediately to upto 72 hours after unprotected intercourse. The earlier the better. The tightening that you are feeling may be non specific and thus does not indicate whether or not the pill is working. You would need to take a home pregnancy test in case you miss your next period to rule out the same. I hope this helps. All the best.