Sorry you're having trouble so soon.
Females can get pregnant at 3 1/2 weeks of age. My suggestion is to split them up now, but assume she is pregnant. Divide the cage with a grid, and make sure the male's half is closed so he can not climb over.
Since she is so young, and probably pregnant, please feed her unlimited alfalfa hay. Also, weighing her daily will help you and your vet know what is going on.
Also, as previously stated, it is helpful to post on the same thread about your piggy. Don't start a new topic, please.
Good Luck.