If the deer is legal, then you have no reason to regret taking it. I've never seen an antler yet that was edible and if you shot a button thinking it was a doe then you were not shooting it for antlers any ways. Personally, I can't figure out the current trend of thinking every deer has to be some sort of monster before it is taken. Enjoy the meat and remember the experience. The first deer is something to cherish, not something to beat yourself up over.