Around here everyone calls pot belly pigs "mini pigs" or "teacup pigs" and says they'll be 20 - 35 lbs full grown. It's a myth, they show pictures of babies from a day to a week old and pretend they are 6 weeks old, have 6 month old mothers so they're small and say that's the full-grown mother. I bought a pig that the owner said was 35lbs. She was closer to 70, but still pretty small for a pot belly. Many adult "mini pigs" still wind up over 100 lbs, and that's if you don't overfeed them so they get obese.
I just had to catch one of my piglets. She is around 10 weeks old. I weighed her. She's 10 inches high and 19 inches rump to snout (stretched a little bit - she was trying to eat the tape measure). She weighed 25 lbs! And she's fairly lean, I'm not feeding them all they can eat but only reasonable amounts 3 times a day plus all the grass they want. (They're a little spoiled because they beg so cutely).
Pot belly pigs are so fertile there are stories of them breeding at 8 weeks old! So very young ones can have babies, and some folks do that to trick people into thinking they're getting one that will stay small. "Look here's the mom, see how little she is?" And they sell them for $200 or more!
And speaking of obese - they're not supposed to have blobs of fat squeezing their eyes shut. Their bellies should only drag the ground the last few weeks of their pregnancy (and mine that had 7 still had an inch or more of clearance). I've looked it up and a healthy pot belly pig should be lean, so you can feel the ribs without trying too hard. When they're too fat they have hip problems, foot problems, fertility problems, and trouble delivering their babies alive.
I had heard that, then I met a woman (who loaned me her billy goat as a stud) who was having a PBP problem - they kept getting her female pregnant before she could get rid of the male babies. She had a piglet impregnate his mother at 8 weeks old, and he got his sister as well, she got rid of him and a few months later there were babies again. At Wind Ridge Farm they cull for early breeding because of the risk and they believe it's unnatural for them to breed so young. Mine successfully bred at around 4 months old and the females are due in August when they'll be around 8 months old, IMHO big enough to do ok since the babies are born so tiny. Not ideal, tho.
My sow that just farrowed a couple weeks ago had 2 females and 5 males. That's going to be a circus! I may have to separate the males out.
Don't count your weasels before they've popped. And now for a mulberry bush related tiny ad:
5 Ways to Transform Your Garden into a Low Water Garden