Should I test?

According to this app I was ovulating between 12-14 & 12-20. I did have unprotected sex during this time. I have been having what I guess are cramps since I don't usually get them. It's just like uncomfortable pressure really in my lower abdomen and back. AF was supposed to start today and usually it comes first thing in the morning. Should I wait a couple days to see if AF will come or go ahead and test?