My baby is 70 days old. Her birth weight is 2.9. During her regular checkup on Sept 24 she was 3.8. Today we weighted again and she is only 4.1. She is on exclusive breastfeeding. I feed her on demand during day time mostly 3 hour once. At night she sleeps for 7 hours without feeding. My pead suggested to feed her at night at 2.5 hour interval. I am worried about her slow weight gain, please suggest if I have to take care of anything in specific any tips or suggestions.