Should i call the dr?

My son is 2 weeks old and last Monday he had to have his circumcision Bell cut off due to swelling and skin growing around it.. tonight i noticed when i was changing his diaper that there was a little blood coming out of his little pee whole. I’m a little concerned and not sure if i should call the dr or what.. he goes to the pediatrician Friday. Should i wait until then or call the hospital? I’m sure it wouldn’t hurt to call and ask about it just wondered if anybody else has heard of this happening before