Becky, I hope your scan goes well tomorrow. I had a few episodes of spotting. Well I wouldn't even call it that, it was more that the CM was stained a brownish colour and I would notice it when I went to the toilet. I totally freaked out too - I had it on 3 separate occasions! Brown blood is normally old blood....it is red blood that is generally the concern as it is fresh bleeding. My OB suspected that what I was experiencing was from the cervix. There is a lot more blood flow to that area during PG and he suspected that is what had caused it.