Clomid

Hello! Anyone here been on clomid? I'm supposed to start this Friday on my CD 1. I've heard some people have had bad side effects from it...are they really that bad or depends on the person? I'm kinda nervous to go on it! Is it only the 5 days while taking it or do they last the whole cycle? I am supposed to go on vacation during my fertile window and am scared to be cramping bad. Just looking for any insight, thanks ladies!