So my 10 day old DS was just lying in bed with me playing about (he doesn’t sleep in bed with me). When I picked him up I noticed a wet patch the size of a small plate on the mattress. I checked his nappy and it was completely clean. His clothes aren’t wet either except for one small area. What is this? I was thinking it could be breast milk but I don’t think so now because it’s a bit lower down on the mattress where DS’s bum was. Weird!