Help..piggies are not same sex!!! Atleast I dont think!

Question
Brittany,
I bought two (female?) piggies three days ago for my little boy. Of course the lady at the pet store said they were both females. Peculiar behavior on their 2nd day home between the two made me start investigating. After doing much research on the internet, I have found that the one is making a mating sound...I have caught this same one mounting the other as well. I have done the inspection by pressing just above the genital area and the one has a little "nub" that pops out...the other just has a little dot like thing.. so i am still unsure. Since this discovery i have separated the two until i can get back to the pet store..and the female who seemed to be under so much distress by the other one, is now making awful noises as if she is heart broken by her partners absense even though she seemed irritated by him/her before. So now the big question... at this age (recently weened) are they able to reproduce, and should i be expecting babies? I am hurt by the pet stores ignorance, because not only do we love both little piggies already, but trying to explain to a 4 year old why they are separated, and also the fact that i purchased them as a pair and to be together and not have to keep them separate!Any of your input would be greatly appreciated!!!

Answer
I am so sorry, unfortunately this happens all of the time with pet stores, with what you are describing you have a male and female. Typically males can get females pregnant when they are 8 weeks old, sometimes you can have males that are mature enough to get females pregnant at 4-6 weeks though. The female also has to be in heat when they mate, which if the male was sucessfully mating with her then she most likely was. The unfortunate part though is if your female is at least 6-8 weeks old then she is most likely pregnant anyways because many pet stores do not separate out their sexes or if they do they do not do it right. It is really hard to tell if you are expecting babies, you should be able to tell by looking/feeling her in about 2 weeks, but if she is the age mentioned you can almost always guarantee it. There is a possiblilty though if she is young that she might absorb her litter early. Let me know if you think she is pregnant and I can give you more information.
Brittany