I don't have a whole lot of advice on the regressing, because I don't have any experience with it. But are you sure he's not been aware of your pregnancy. I know it's early but that might be something. On the peeing standing up. Ds 1 peed on the potty sitting until he was probably 3 yrs old. He was a neat and clean when he peed and he even wiped up the potty, now at 6 yrs.....not so much.
6/15/12 at 6:28pm