don't worry about baby drinking less milk at this stage - my baby went through the same thing at that age. So long as baby is gaining weight and growing normal, no need to worry at all. The earliest to feed solid to baby is 4 months (if you give solids too early, their digestive system and body cannot cope and you will harm your baby). You must consult your doctor first if you want to start solid at 4 months. I started on solids when my baby was 5.5 months and even then, I only started with a small amount of baby rice cereal (like 2/3 teaspoon to start with) for tasting (rather than as a substitute for milk).