My 2 month old baby has this "habit" of drinking bit by bit... Be it either formula or breast milk... Isit normal? And also is this "habit" to be worried about?

Could it be the teat is not suitable for your baby? Because the texture is different for every brand. My son takes pigeon well, but for medela or avent he rejects or when he's very hungry he will take in bit by bit but not want it fully. Could be the teat. Try changing to different brands.