My daughter is 9 days old.. i have flat nipples so she has latching problems.. i try to breastfeed her but coz of latching issues i have to use nipple shield to feed her.. after feeding for almost more than 1 hr.. she is very cranky and demands for milk.. in between sometimes she pee for 2 to 3 times.. and then to full fill her stomach i had to give her formula milk.. is it fine or is there something to worry? what should i do to full fill her stomach??