I'm not sure if April is remembering a post or an email I sent her(wink), but I left my male in until about 2 weeks before the female dropped the babies. It was my first time breeding, and to be perfectly honest I wanted to make sure she was definitely gravid. My male was much smaller than the female, so I felt a bit more comfortable leaving them togther. He actually continued trying to breed her up until about 2 weeks before I removed him. For some reason he never stopped showing interest in breeding, could have been because he was inexperienced, who knows? I have to agree with April though, I would think it would be better to pull the male. I have a pair that are courting now, and I have really been paying much closer attention to what has been going on, and I plan to pull the male after the POS.
Hopefully some one with more experience can give you a more concrete answer. I think that I probably should have pulled the male, but she did drop a good litter, so no harm, no foul.
Good luck,
Rick S.