I would also get it checked out,....
Emma was fine until my supply started to even out. Then she didn't have the power in her tongue to get what she needed. We really only ran into difficulty around the 6-7 week mark.
Because I had had such an easy and positive bfeeding relationship first time, nobody looked at me with Emma (Oscar was easy-peasy from day one to his self-wean, in this aspect at least;-)
Tongue tie can be spotted by you though - when he's crying does his tongue look heart-shaped? When he's rooting and wanting to feed, can he stick his little tongue out?
S x