first off, i've been doing this a month.. I "had" 4 females pregnant. one passed last night while giving birth..
From my research I came across they become fertile every 4 to 5 days. So how I do mine is I leave the male in with a female for 5 to 7 days, and then alternate between them. You really can;t see signs of pregnancy early on till about day 15-19? (IMO so far) so i continue to alternate the male until i visibly see the female become "fatter" It's easier then what you're trying to make it. Trust me, I started like that but just did some research and watched and now i feel okay. Am I saying I'm a expert? no. :o but i can help you with what i've learned.
just dont stress it to much. just let them do there thing and you'll be fine and hopefully have some babies soon enough!