Should I wake my baby up for his fifth bottle?

Frances

So my baby is 3.5 months old and is putting on weight very nicely. Loads of wet and dirty nappies. He went to sleep at 20.30 which is alot earlier than usual as he normally fights sleep. However he has only had 4 bottles and normally has 5 a day. Now I am not one to wake up a sleeping baby and know he would let us know if he was hungry. Should I let him sleep through if he doesn't wake for his bottle at 21.00?