I am not on birth control and I have a very irregular period. By irregular I mean that I have gone almost 8 months without my period. The only way I know that I'm about to get my period is when my breasts are sore. This is also known as my time of ovulation. So, I was not ovulating when I had unprotected sex and he pulled out just in time to ejaculate. I know this method is not effective, it was a stupid spur of the moment. Just in case, I took the plan b one step pill 30 minutes after unprotected sex. I would like to know what the chances are of getting pregnant?