Chiming in, too. With my DS, I spotted AND cramped for 3 or 4 days at around the 7-week mark, and they brought me in for an ultrasound, but there he was, chugging away and little heart beating like a champ - the tech said he was JUST big enough to see the heart on the U/S, hence his nickname for the entire pregnancy, "rice krispie" - that's what he looked like to me on that first picture of him :LOL
My spotting was also darker, not bright red, and mostly when I went to the bathroom, so I'm sure it was "old" blood, too...it lasted a few days, and then resolved, both the spotting and the cramping.
Just wanted to let you know it can be perfectly normal, but I also wouldn't blame you for wanting to get it checked out. I probably would again if it happens to me this time, too....I'd rather know than wonder.
Heather, WAHM to DS (01/04) * DD (06/06). Wed to DH(09/97)