Not sure what to think?!

I'm not sure if I even ovulated this month as any opks I took weren't really near positive. It is our first month ttc/first month off pill. If my cycle stays regular, I should get my AF tomorrow. But im having pinkish discharge. pregnancy tests are negative. Not even vvvfl that I can see. Could it be implantation bleeding or AF showing up (which would surprise me first month off the pill).