Feeding time

Hi, my baby is now 9 weeks +, he is drinking formula i.e. Frisolac & Dumex. He always cry for feeding every 2 hours except midnight he will only wake up once (4 hours). His weight currently reaches 7kg and he is getting chubbier day by day. I m not sure if his weight consider healthy or i've overfed the baby bcoz i supposed 2 month old baby should demand for milk every 3 to 4 hours instead of every 2 hours. Anyone mind to share ur experience please?