Spotting confusing?

Hey girlies, I'm really confused so AF is due today and didn't show up, I had a little bit of pink discharge once today just when I wiped and that was it, it's now the end of the day for me and nothing else at all? I'm usually only ever early never late. I've recently had really sore nipples, little pulling feelings in my stomach and a little bit of sensitivity to smell! Anyone had this? Is it normal to spot just once and be pregnant?? Pls help💕💕