QKs 50NL

Villain is unknown.
I think my play up to the river is standard. (I would usually 3bet this but I had just sat at the table I so wanted to get a feel for the other players first.)
My plan was to call on the river. However when he ships it I'm worried as I don't think most people will bet this much with AK or AA. I'm dead to any set, but I block KK, and I think a lot of people fold 44 33 pre in utg. Not worried about QQ as he shouldn't be betting that big on K high flop. I'm also dead to AJ and J9 of diamonds. I think he can be bluffing with missed flush / combo draws sometimes, and I also expect to chop a good % of the time.
I didn't feel good about the call but I felt my hand was too strong to fold.
Thoughts?