Bleeding around o is pretty common. I've never experienced it myself, but I know the books talk about it happening to a lot of women. (although, just because you have it this cycle, I don't think that means you should expect it every cycle, or even ever again. I think sometimed it just happens.)
As far as implantation bleeding, I had bleeding around the time of implantation with both of my pregnancies. I've heard before that it is just a myth, but try to explain that to my pink-stained undies 5-7 days after ovulation!
I know that not everyone experiences it, but I sure did.
Also, although I think she was using the term loosely, when I went into the dr. for an emergency visit because I had some bleeding at 6w6d, she called the bleeding implantation bleeding. She said there is so much going on in the uterus in early pregnancy with the babies attaching (I have twins), the uterus stretching, things shifting, that bleeding is actually quite common, and she calls all of that "implantation bleeding."