Signs of labor?

How did you ladies know you were in labor. As far as I know, my water hasn’t broken. However, since 8:30 pm last night, I have had runs and vomiting with cramping-like symptoms. I just wanna hear different labor stories. When do I say enough is enough to the throwing up. I’m not trying to be that woman that goes to the er, but I’m not keeping anything down. I’m currently 37 weeks pregnant. Any insight would be helpful.