My snail doesnt want to mate, persistant male

I have two Black Mystery Snails and they have mated many times before, of course no eggs yet. But the last couple of days my female has been stuggling to get the male off of her shell. I finally sperated them and the female went to sit at the top of the water. Is she just carrying fertile eggs or is she just not in the mood? I dont know what else to do, I wanted to get more snails for my other tank that I put the male in, but if I cant have them together then I dont think that is an option. Thanks-Janell

thanks, hey what do you have in your fry tank besides fry. I want to put something else in there that wont eat them but I think snails are about it.