Implantation bleeding or period?

Kind of long, but if you're willing to read I'd love some input :)

I started Provera last month for PCOS and because I wasn't ovulating. I went off after 10 days, and had the heavy bleeding and all that jazz.

About 6-8 days ago, when I was estimated to be ovulating, hubby and I had sex twice. Now, about 7 DPO, and 2 days before my second round of Provera, I just noticed I'm sort of spotting. It's bright pink almost, and light.

I guess my question is this. Is there any chance it's implantation bleeding? I did take an ovulation test at one point and it came back negative, so I know that means its very unlikely. Is it more likely that its the beginning of a period because I'm not regulated to the Provera yet? Any insight would be appreciated!