Late Period

So eve is telling me I'm late by 6 days.  I've had irregular periods in the past and have PCOS. I currently got off of my old birth control because it was making me puke. I'm only worried that I'm late because of that fact that I had sex for the first time in awhile a few days before eve told me my period was supposed to come. The day it said that I was supposed to get my flow all I had was a little bit of spotting for a day and I feel as if I'm still PMSing like a motherfucker. Should I be concerned about pregnancy or is it just my body and it's hormones balancing out from getting off my old birth control? Please let me know what you think!