Baby is turning 1 month tomorrow! My baby is so thin!

Edd: December 7 December 7, 3pm : I went into labor starting at 4cm until 12mn December 8: my cervix opened from 4cm to 6cm then 9cm. I delivered my baby via normal at 7:12am after 3 push. It was painful but all worth it. My baby weighed 3.06kg. Since my UTI was not yet cured, my baby got the infection. He had sepsis but thankfully, he was cured after series of antibiotics. We got discharged from the Hospital after 7 days, Dec 16. Now, He's at 3 weeks and 6 days. He'll be turning 1 month tomorrow! My concern is, my baby is really thin kahit matakaw po sia sa breastfeed. Payat po sia.. Any tips po Para tumaba baby ko? Thank you#advicepls #1stimemom #firstbaby