Contractions??

I am 39+2...I woke up this morning at 2am with some bad (but bearable) cramping. I noticed that it would come every 10 minutes or so and it felt like a belt where it wrapped around my lower pelvis, hips and low back. It would peak and make me wince (but again I found it bearable) and then slowly fade off. I assume these are contractions? FTM

Anyways, I started timing them...it was happening every 10 minutes for 3 hours. But then now it’s gone!! WTH!?! Also I lost a lot of plug that had red on it.

Is labour soon?? What are your experiences? Why did the cramps go away?