My son now seems to like laying flat on his back (we have him in the Rock N Play because he HATED being totally flat when he was born). However, I find when I lay him on his back for an extended period of time, he tends to pee up the side or out the back of his diaper. I can't figure out for the life of me why this happens as I check to make sure his diaper is on well. Also it only very rarely happens if he is at an incline (in his swing, carseat, or rock n play). He wears Pampers Swaddlers (have also tried Huggies, have had same issue) and he's wearing size 1 and is 9 lbs (supposedly perfect size). His penis naturally points upwards and if I try to point it down it seems like it would just get squished in the diaper. We want to transition him to his crib since he's 9 weeks, but I worry about all of the accidents!

Anyone else have this problem? Suggestions?