I had so much pressure from my inlaws to bottle feed around that time!! Do whatever you feel is best for you and bub and don't listen to anyone else! Agree with a PP that 4 months is a growth spurt time and apparently your milk changes at 4 months too according to my CHN! I stuck it out and DD2 is 6 months now and still breastfed! She is sleeping well and feeds 4 hourly with solids in between! Don't let them get to you but if you decide to try formula that's your choice too!! Its your baby and your body so ultimately your decision alone!!!