Are pregnancy symptoms consistent?

Do pregnancy symptoms come and go? My husband and I have been trying for 4 months, this last week, I've experiencing Heartburn Headaches, frequent bathroom breaks, moody, Sore BBs, I have been thirsty all the time, my hands and feet are itchy, bachaches on and off then my whole body is stiff. then all of a sudden the last day or so i've been fine. I was to start my period last week but she didn't show. Can pregnancy sympotoms come and go????