First of all...
Not many people will see your post here, you need to put it in the "breeding" section of this site.
As for your problem, I don't know a whole lot about breeding but I'm not sure that a yearling even CAN become pregnant. Maybe I'm wrong.... I don't know. But yes, you should have her looked at by a vet.
Post in the "breeding" section of this forum and you'll get more replies from more experienced breeders.