Yeah, I'd agree with the others especially with a male around since they are super good at getting where they shouldn't be. They'll even commit the act through a wire fence if the holes are big enough. You might want to look into deworming but definitely make sure they're getting a good...
When did you get the goats, or do you have a male goat? Is there a reason to suspect that she's pregnant?
Have you had fecal tests done/dewormed them recently?
What have they been eating as a complete diet?