Red Nosed Pit, in heat, puberty or pregnant??? PLEASE HELP!!!?

My Red Nosed Pit, Sadie Grace, is 11 months old (to be one year in June, 2009). My husband and I took vacation and kenneled her from April 23-May 2. When we picked her up from the kennel, we were advised and quickly noticed that she was in heat/menstruating, but we were not told how long she had been that way. We have no other animals and an eight foot privacy fence surrounding a big back yard, in which she loves play. She quit menstruating about a week ago but her body is still changing. Her are bigger and sticking out with what looks and feels to be sacks and she is getting thicker. I want to believe this is my little girl turning into a full grown *****, but I am really beginning to think she got pregnant somehow. Could she have gotten pregnant in the kennel and still menstruated for four weeks? Could she still just be in “puberty?” She has not been exposed to any other animal, that we are aware of, since we picked her up. Am I going to have to deal with puppies in 4-6 weeks?????? Any information would be greatly appreciated. I do not want to take her to the vet if this is normal and she is just "blossoming." Thanks a bunch! D