Wieght gain is inadequate. The problem is most likely with the LATCH (the way the baby is sucking or holding at the breast). If baby isnt holding properly at breast, you may feel baby is sucking and your milk is good, but good amount of milk doesnt go in baby s mouth and that's why baby s hunger isnt satisfied after you feed.
Next Steps
best is to get a physical consult. but if you stay far away, you can take an online consult also. I am a certified lactation consultant.
Health Tips
target weight was 3.9 kg. weight is too less. please consult as soon as possible to prevent loss nutrition to your child