3 week old baby un-settled, colic?

My 3 week old baby has started to be very unsettled, more so after around 5pm. Not constant crying but unsettled when put down crying on and off, red faced screwing his body up. Spoke to health visitor and suggested changing his milk to a comfort one which i am going to give him tomorrow. Is it worth me trying some infacol too? He is feeding fine but seems to wake every 2 hours after 5pm sometimes less acting un-settled and in pain but i can never get any wind up, clean nappy and has always not long had a feed