3 month old a little lighter than expected

You should check the weight chart in the Health Booklet. As long as baby stays in the same percentile since birth, you shouldn’t be worried. Even if drop percentile, they can always catch up in the later months. Mine was born only 2.5 kg but is now a chubby 9 kg at 8 months old.

I wouldn’t worry if baby is eating and sleeping well, all happy and healthy