Labor signs?

Nena
Can some of you ladies please tell me how you knew you were in labor? I've been having pelvic pressure & painful Braxton hicks along with diarrhea for two days now & I'm 34 weeks. I'm worried but I don't wanna go to the ER looking like a dummy ... So please if you could share with me about how you knew you were truly in labor, I would appreciate it!