Pumping only

Is it ok to strictly pump and save the  colostrum/ milk. My boobs are so engorged I did pump and got a lot out. I fed her that in a bottle and she took it almost better than the breast. & she is eating more without spitting it up.. We feed with a nipple shield do to flatter nipples. I feel like maybe she is getting to much at a time when she BF. & she gets frustrated when I take it off and try without.. Help me first time mommy here!