Thank you for all the suggestions. In the end I couldn't leave him to cry so I gave him a feed. He went straight to sleep after and has been sleeping 2.5 to 4 hours at a time since. I don't know why he was so upset. Now he is back to his happy little self.

Barb Glare, the birth was long (18 hours), he was in distress and I had an epidural which stalled labor. He was born 8lb and is now above his birth weight.

Thank you everyone, I really appreciate the help and support on this site as we don't have any family here and none of our friends have kids. It is really hard when we have little problems like this and the midwife tells us something that doesn't sound right but we don't know what else to do.