Some women get a tiny bit of spotting when they ovulate. Not most or many but it happens. we have all sorts of hormones going on--- especially when ovulating. So, that would create spotting. Also, some women get a bit of blood during implantation. So, maybe you ovulated a bit early and if you are trying to get pregnant, you are. So, wait until your period is due and if it doesn't show, take a test. But generally, this is nothing to worry about. good luck
If you're really concerned, I'd say go see a doctor. It could be anything though. If it's not bothering you, wait and see if your period is late and test after that.