Help!!!!

Lacey • Ttc for 8 months. Trying for baby #1.
My AF is three days late  and for the past week I have a weird feeling in my lower left side of my stomach. It's not really painful just feels weird. It comes and goes lasts up to 20 minutes than just disappears. Haven't taken a test waiting till I'm a week late. I have been late before bit have never felt this.