36 weeks pregnant and i have some questions!?

lately i have been having diarrhea and i pee ALOT! i noticed that my lower stomach is squishy not hard like it usually is....also i have been having alot of menstral like cramps, they keep getting worse, i cant sleep at night very much...and my lower back is starting to hurt a bit, the cramps arent exactly in a certain pattern, but they are getting worse, what could be going on? do you think im going to start having contractions? how long does it take to have the contractions go in a certain pattern? also i have been losing my plug for a week and a half now!