Milestones

Ok so my son is a little over 10 weeks and i'm looking at 3 month milestones, he has brought his hands to his mouth before but he hasn't done it in a while... he is opening and closing his fists but still mostly keeps his hands at his side, doesnt reach for objects or put weight on his forearms during tummy time, he mostly pushes himself up with his hands.

Does this sound odd to anyone? I'm just worried about his motor skills with his hands and arms.