I'm 4w5d pregnant, and for the last several days I've been experiencing some fairly strong pain in my sides.

I can't quite describe it - it's sort of like cramping, kind of like a stitch in my side like you would get after running.

My friend is telling me it's round ligament pain from my muscles stretching, but isn't it early for that?

In the back of my head my paranoid self is going "Ectopic Pregnancy?"...

Anyone else experience this?