plan b

My girlfriend took plan b a week before her period was supposed to start. She started the next week and it was a normal period(32 days: she's irregular), and she also got off Birth Control. Two weeks later she started another period with heavier bleeding and it lasted as long as a normal period would also. I'm wondering if the second period was caused because of PLAN B? or was it a normal period? because if it was caused by plan b then she should be starting now, but if it wasn't she should be starting in a couple of weeks. Just wondering if you could help me out. Thanks!

[Elaine Brown, MD]

HI!
Why did she stop birth control?  If you two are not ready for a baby, I'm not sure that's the wisest plan.  Yes, the Plan B probably did cause the second bleeding episode.  Plan B usually works by delaying ovulation, and delaying ovulation delays the period.
When the next period will come is difficult to predict (that's another reason to continue birth control--it regulates the cycle ) but it should be within 4-6 weeks.  She may want to check a pregnancy test ( I ALWAYS recommend that!) just to be on the safe side.
Also remember, the rhythm method doesn't work for women with irregular cycles ( or even regular ones for that matter) and withdrawl (withdrawal) is not very safe either.  
You two sound like fairly responsible partners, so I'm sure you'll make a good decision.
Good luck!
Dr B