I'm spotting

I never had any bleeding with both my boys so this is worrying me a bit. I'm only a little crampy, no more than I have been and the blood is a very very small amount when I wipe. It's sort of mixed in with clear cm. 
I'll call the early baby unit in he morning. Has anyone else experienced this? I know it can't be implantation bleeding as that occurs at 4 weeks, I'm 6 weeks