26 weeks and having contractions

I'm actually 25+6 today, but I just round up to 26 weeks. Close enough right? Anywho, started having contractions weeks ago, but very random and they were more annoying than anything. until today where they were actually pretty painful and somewhat consistent, but have slacked off greatly. Is anyone else experiencing any contractions this early? I've put a call into the on call doc, but just curious if anyone else has felt any contractions yet. Am I over reacting by calling the on call? Experienced advice is welcomed.