short feeding/sleeping/fussiness question

Jane
So my son is almost 10 weeks. 13lbs and EBF. As of yesterday he's been very very fussy, hardly eating (one boob at a time usually takes both and for a short time), he's been burping a lot even when I burp him and keeps crying if I put him down. His temps are fine and he has peed/poop. Is there any other reason for these habits? It's not normal for him. I also wonder if this is effecting my milk supply as he usually takes both.. when he does feed it isn't strong, more week feeding- like barely sucking..