Is spotting during a period sign of pregnancy?

Shay
My period came on January 14 like normal with cramping and clots... My flow was medium which is normal for me but what wasn't normal that in the middle of my flow day 3 I started spotting and im still spotting and its day 5 of my period.
I did have unprotected sex the day before my period started
Extra info on me I have PCOS with a cycle length of 30 days... I have a period every month that last 5 days with a medium flow... I never been pregnant (no miscarriages no false positives) but ive been trying for 4 years
Any suggestions of what could be going on would be very helpful.