Your female is pretty much guaranteed to be already pregnant, and will be for a good long time, even after she gives birth to her batch. So don't worry...they've already on their own, and it's doubtful your male is the father. She's probably carrying 6-7 sperm packets within her body from previous males' inseminations, so, even without the male there, she should give you fry every 2 months or so in good conditions.
When she runs out of sperm packets, or if he inseminates her after she has given birth but before she has used a sperm packet, then your male can father fry with her.
It would be really good for her if you would get another female. The male's attentions can be a little too much for just one female to take, and, believe me, eventually, he will probably notice that she is a girl. Two females divides the attention from the male between them, and makes it tolerable. Livebearers should always be kept in at least a 2:1 ratio, with at least two females to each male.