Rescued Guinea Pig Preggers?

Question
Hello Pat,
What you said to the other person who asked about an older guinea pig having babies made me feel a bit better. I recently took a female guinea pig in. A fireman rescued her from a burning building and she was in a very small cage and the old woman who had her could not keep her. My son works at a pet store and the fireman brought her to them after bringing her to the vet. Supposedly the vet said she was one to one and a half years old. My son took her home and we have been loving her for the past month. two weeks ago we were away for the weekend and a neighbor watched her for us. She send her there in the small cage she came with (now she has a two room apartment:-) but they already have a male and let them out to play. The grandma said she saw the male on her and told the little girl not to let them do that, the little girl said they were just playing, and the grandma told her the guinea would hurt her back. I do not know if the kid took them out when they were unsupervised but I am trying to trust that she didn't. And I do not know if this was the only time and how long he was on her. This may sound like a dumb question but how long does it take a guinea pig to get another one pregnant? I am only worried about it because we love her but we do not know exactly how old she is. I don't want anything to happen to her. We snuggle on the couch and watch TV together every night. She's my best buddy.

Answer
That was a good save by Grandma.  Guinea pigs don't get pregnant that easily and I doubt if the male actually finished the deed.  Of course you don't know if that was the first time they were together long enough to actually cause her to conceive.

Rabbits are spontaneous ovulators and will conceive almost on command. Guinea pigs do not. I truly doubt that he impregnated the sow so I wouldn't really worry too much if I were you.  Of course if the deed is done there's nothing you can do at this point. You will know for sure in about eight weeks.  The gestation is ten weeks but she will be obviously pregnant and showing in eight weeks.

The girls come into estrus on a fairly irregular basis, meaning the ovulate about once every two or three weeks. They aren't predictable as other animals are. They are only vulnerable for a few hours during each cycle. That's why when we're breeding we leave the boar with the sow until pregnancy is obvious.

In other words there may be nothing to worry about at all. If the sow was not ready to mate she would have let him know it immediately.  She will shoot a stream of urine right in the face of her 'aggressor.' That usually cools their jets fast.

Let's hope that there's nothing to worry about, it won't change anything anyway. And if it turns out she is pregnant you'll just have a couple of extra fuzzy faces to cuddle with!