Beginning of period or implantation bleeding?

Ashley
Last month I started spotting a few weeks before my period. That lasted a few days, then a few days later I got my period. That lasted for more than a week. When it slowed down, I started bleeding heavily again. Went to the doctor since I've never had that happen before, it definitely scared me. The dr checked for pregnancy, negative. He just thought that my body started my period over for some reason. The next day my period just stopped. 
​Today I stared spotting and cramping. My period is suppose to come in 10 days. My Husband and I did have unprotected sex when I was suppose to be ovulating, a few times. I'm not even sure if I was ovulating though. We are not TTC, but we're not trying to stop it from happening either. 
​Anyone have any ideas? Have you had periods super early or had cramping during implantation bleeding? I will test if my period doesn't come, but I'm just so dang anxious! Thanks!!