Started baby food at 4 1/2 months old

So my little one has been showing an interest in in food, I work part time & when I'm gone she does 4 oz of formula plus an ounce of breastmilk, when I'm home she usually just nurses. At her 4 month appointment her pediatrician said that since she has good head control she's able to start foods, but on here I see so many people saying not to start until 6 months. I have already given her pureed foods a few different times, Bananas, apple, peas, butternut squash....she does really really well eating off a spoon & loves it halve been doing it for maybe a week....but today she has been pretty grunty even after a good poop. I can't help but think it's bc of the switch to food. I can't decide if her little belly is just adjusting to it or if I should stop for now?