So, my 5 week old never latched due to my short and flat nipples. I am exclusively pumping and it is getting draining. I on occasion supplement with formula but hazel gets awful stomach aches and constipation with formula so I try not to give it to her. I have nipple shields but sOrt of gave up on trying to feed her with them. Is it too late to try? At 1 week, she was not receptive to it at all. Any helpful hints?