Ball Python feeding help!?

ok, i got my python 3 days ago. the guy at the store said wait three days to feed it. so ive waited, now i dropped in my thawed out frozen mouse into the cage. its been a couple a days and i know pythons are picky eaters but the mouse is bloody so obviously he bit it a little bit. but do i just leave the bloody mouse in the cage? or take it out and refreeze it. the head is just slightly bitten. I feel like i should leave it in there cause he hasnt ate in like a week