I had unprotected sex and then I got my period about 8 days early. It started out brown and didn't seem normal then lasted 3 days which is normal length of time for me. But since it was so early I Took an hpt which was negative but may have tested too early. Now, during sex today there was some light bleeding and this is about the time my normal period should have started. Experiencing a little nauseousness but not sure what to think?