When should I test if Aunt Flo is a no show?

My husband and I had unprotected sex on Saturday the 18th. He pulled out, but I was ovulating (whoops). I’m still breastfeeding our baby who will be 1 Saturday. I heard u can’t get pregnant when nursing and now I feel dumb for believing that considering I have had a regular period since she was 8 months old.. My period should be here in 2 days. No sign of it yet.

**to add** We were not ttc or ready to yet, but I’d be happy with another if that’s what happens. I know there’s a chance I could get pregnant every time we are intimate, but it was spur of the moment type thing with my HUSBAND, so I really don’t feel bad.