Spotting after sex

Nicole • Married 6/13/2015 Mommy to little boy 11/22/2018 Ttc baby #2

So me and my husband had sex afterwards I started spotting I am three days away from my period I normally dont think much into it but after like a 1hr or 2 the spotting stopped. Could it be my period or could sex have caused me to notice implantation bleeding