Baby hasn't peed

Kayley • 24 years old, I have a little boy who’s 4 and I’m TTC my second baby!! 👶🏻
My son is 7 weeks and i change his bum every 3-4 hours and its always without a doubt full of pee, i just went to change his bum after 4 hours and its bone dry , not a single pee. Should i be worried?