Re: pumped early on - is it milk or colostrum?
It's fine to give the milk to him now, or at any time. If your mature milk was "in" at 5 days postpartum, what you have frozen is likely "transitional milk", i.e. mature milk mixed with colostrum.
May I ask why you're pumping, and why you've been pumping since so very early on? Is everything going okay with nursing?
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"