Big eater during pregnancy

Initially I cant eat much due to heartburn and bloatedness, so i had small meal throughout the day. Now I eat as normal, I get nausea whenever I am hungry. 2 week ago, I started to wake up in midnight 1 to 2 times to have food like hot milo and biscuits. If I drink the packet milo, I still feel nauseous and cant go back to sleep. It really affect my sleep and I get migraine on and off. Sometimes i ate supper before bedtime, but still wake up once to drink milo. I have gained almost 2 kg at my week 8 now. From 46 to 48kg. I am not sure is it bcos I was big eater before pregnant. My tummy look big like many mths when I am full. This is taken after my normal dinner.