I agree with taking some Advil, but I would also take a pregnancy test. Last year (about this time of year), I had in the Mirena IUD and started having some cramping, as well as some other symptoms. I didn't know it at the time, but I had an ectopic pregnancy. It is rare, but can happen. I dealt with the cramping for more than a week before it got really bad. In the end, my best friend saved my life by calling an ambulance, then my husband and I were shocked to learn that I was pregnant. I thought the ER doc had my chart mixed up with someone else. They did an emergency surgery and removed one of my fallopian tubes, which we had learned had burst and my abdomen was filled with blood. Everything turned out OK, but I'm so grateful that my friend forced me into the ambulance. She literally saved my life. I was bleeding internally and would never have let my husband take me to the hospital because I don't like being the center of attention.
If I were you, I would take a pregnancy test to rule out a possible ectopic, then take some Advil until you have the chance to get into an OB. If you feel, at any point, like something is really wrong, you should go to the ER.
Good luck. I hope that this mild cramping just ends up being mild cramping that is really nothing.