Baby's weight

I'm just a little sad ?. My baby's weight when she was 2 months old and 6 days was 4.9kg. When I went back to the center yesterday for the scheduled immunization, I checked her weight again and she was only 5.0kg. She's 3 months and 4 days now. I'm really worried. Maybe she's not getting enough milk from me? She's a breastfed baby but she seems small. She doesn't show signs of having health issues, in fact, she's a happy baby who doesn't like to be put down when she's not asleep and just wants to be cuddled and talked to. I'm just really feeling down.