Period Like cramps. 11 weeks

I am 11 weeks today and I have had some fairly uncomfortable period like cramps in my lower abdomen and lower back for the better part of an hour. I have called my OB office but I am waiting for a call back from my dr. I am just wondering if anyone else has experienced this. I am a FTM who tried for a long time to get pregnant and I am trying to just stay calm but oh boy this is uncomfortable and I don't think I am to be this uncomfortable so early on. Please someone calm my nerves.