guinea pigs

[NancyBee]

I have a seven year old female guinea pig who I love to bits. My son bought me another female for me from a pet shop who turned out to be pregnant. She had 3 babies, I kept the one I thought was female and gave my son the 2 boys. However, this so called girl has also turned out to be a boy and I am really worried that my old guinea pig might be pregnant. I know it is usually fatal if they have their first litter after the age of one as the hip bones are fused and cant open for the birth.
Has any one experienced this? I am taking her to the vets but if she is pregnant that wont solve the problem