Trace of Blood in CM

Jamie

I understand a lot about the science behind a period and Baby.

But this has me confused! I did have unprotected sex with my husband a day before my period was to start.

I should ovulate on September 2nd.

However, I have a trace of blood in my CM.

My question, have you ever had trace blood before ovulation? Or is this probably implantation spotting and I ovulated early than expected?