Contractions at night

FTM - 39 weeks- question. Last night I was up ALL night probably every 15 or 30 minutes waking up to what I think were contractions? I have been having mild contractions the last couple weeks but nothing like these. Some were only like 10 seconds others were more like 40 to a minute. I was obviously sleeping so I didn't really time them but I know I was having some several an hour. It felt like a horrible stomach ache or horrible period like cramp. This morning I had diarrhea. Was also having some pelvic and back pain. This morning I got up and was walking around a little and only felt like two or three of them the last couple of hours but they seem to have dwindled from last night. False labor? Early labor ? Does this happen regularly towards the end of pregnancy ???