Re: advice on sex?
Women ovulate about 14 days before the first day of their next period, so if you're irregular, it's pretty much impossible to say what days to avoid in addition to using condoms. You could try paying close attention to your discharge, any cramping or any other signs to see if you can tell when you're ovulating, and then don't mess around then. That's about all I can suggest.
If your boyfriend always uses a condom and he always pulls out, you should be pretty good.