Advice. Probably just paranoid

I had unprotected sex on the 4th (stupidly in the moment, was a quickie) with my fiance. My supposed ovulation date was November 24th, I have a 37 cycle so aunt flow was due today, shes a no show. I know it's too early to test. I am exclusively breastfeeding my 11 month old. The odds of being pregnant are low 13 dpo right? Probably just due to breastfeeding?