Will someone help me? I am so confused! 10 pts here waiting!?

I am having some cramping that is too late for ovulation cramping but too early for AF cramping! I am on CD 19 according to my OPK i should have ovulated friday i did experience some light cramping, it has not gone away. I am also using pre~seed lubricant & taking pre natal vitamins which i have been on for 2 month now & they have begun to make me feel nauseous! I know this may be TMI but last night when i went to apply my pre~seed ( it goes up in you ) there was a small amount of blood! What is this? Implantation cramping? I thought it might be too early for that PLEASE HELP.. Much thanks in advance