3 month old don't want to take his milk

Hi mommies has any one experience here baby not taking milk or when u feed him he will not take it and play the nipple bottle only? My son is going to 3 mos and is v. Difficult for me to feed him now I still need to talk to him so he will finish his milk sometimes he doesn't want to drink it, I am worried as he drink little bit and every 4 hours