Don't have sex without 1) a condom and 2) the girl on the pill. Don't do Depo because there was some recent study that said it weakens bones. If you follow those steps, there shouldn't be any concern if you're banging someone you know and trust. Unless a girl has a really light flow, she's probably not going to get off if you make it during her period. I wouldn't go by any health class teachings as far as whether or not an egg can be fertilized at a specific point during menstruation: it's not worth it to let loose inside your girl if you don't want a kid.
