Diaper mishaps

Jill • FTM to our one and only Neal.

My LO is 12wks on Monday and I moved him up to a size 2 (Pampers swaddlers) a week ago because he is a peeing champ and was leaking through size 1s after being in them for just over an hour. However....since switching to the 2s, the pee is contained, but we have poopy mishaps every time! Comes out the legs usually! 1s are definitely getting tight on him and the 2s seem like they fit very well, so I'm confused as to why we are having issues. Are they too big? Too small? Im soaking and washing clothes pretty much every day because of the leaking poo. 😵

Any suggestions much appreciated!