4 weeks pregnant and don't feel like it.

This is my third pregnancy hopeful this will be my second delivery.   I'm worried because I'm not cramping at all. Last week i remember my ovaries hurting off and on but that's it. I don't even feel as if I'm about to start my period. 
Last pregnancy I cramped the whole time and I kept feeling like I was about to start my period even when I got a positive pregnancy test. Has anyone been pregnant and not have any cramping and still have a healthy pregnancy?