Are these signs labor is close or can this last for weeks?

I'm 36 weeks and last week was 1 cm dialated and Dr said baby was low. I had a couple contractions (I believe they were real ones, they started at top of uterus and radiated down) last night and cramps in lower abdomen throughout the night. This morning I'm nauseous and have diarrhea. Thanks, FTM don't know what to expect.