My female guine pig was bleeding from her rectum (and has been littleby little for 2 days).?

the vet says that its because my male (not neutered) has mated with the female. she's been giving a little blood for two days. i've separated the pigs. is this normal? vet's saying that guinea pigs have induced periods. as in they get periods only after they get pregnant. what to do? is this correct? im going to get the male neutered right away. is the female okay?