In Oct. of 09 I had unprotected sex and took the plan be the same day. Ever sense I have my period coming every month but different days I never no when it comes.. does any one no why the plan be done that... and could I have a hard time getting pregnant.. sence my periods come at different times of the month.. please help

Plan b is basically just a huge dose of hormones. So that's why it throws off your cycle. You may want to talk to your dr though if you were previously regular and are still irregular now after so many months. Always better to make sure nothing is wrong. It might be harder to track your ovulation, but otherwise you should still be able to get pregnant when you're ready. Again, best to check with your doctor to be sure though.