early labor...?

Do you always have contractions in early labor? I feel sooo sick right now, there is sharp pain in my stomach muscles and I'm really off. I have a doctors appointment but they NEVER start on time (appointment was at 3:30 and it's 3:50 and still haven't been called back) I'm just wondering because this is a new symptom. I'm 34 weeks pregnant but baby has been measuring two weeks ahead for almost the whole pregnancy so she's measuring at 36 weeks. I'm so miserable sitting in this waiting room I feel like I could scream. ESPECIALLY since people who had appointments after mine are being called back. It's like they forgot I'm sitting here!