10 day old baby boy worries

HT
hi... my baby boy is 10 days old today.... i am exlusively breast feeding my baby.... the last 9 days were fine but today he has not been pooping well just 2 dirty diapers in 18 hrs previously he pooped after every feed. further he has been vomiting (just milk) after the feed ( 3 to 4 vomits today).... i called my midwife and she said its nothing to worry but im really worried.... the baby hasnt been winding as well he appears to be putting pressure and then cries but he doesnt poop... please give some advice