You need to keep your female completely separated from the male for at least 21 days. Some bitches have been know to conceive very late in their heat cycle. If they are not jumpers you could keep one in a tall x-pen but if they are in the same room it will be more frustrating for them. My suggestion is to keep them in separate rooms. I know they will be unhappy about this and it requires a lot more work on your part but it is the only solution to keep your girl safe. Good luck.
