Braxton hicks?

Lily-Anne • Fighting PCOS. 2 losses.
I've never had braxton hicks before, so I don't know what they feel like, but for the past few weeks I've been having really bad period pains in my lower back, which haven't been too painful, but today, instead of the usual period pains, I was experiencing cramps. 
Excruciating cramps.
They started in my stomach, before working their way into my ribs and back, and were so painful I almost threw up. 
They were in intervals, maybe every minute or so and would last for about 2 minutes. 
Changing position would relieve them for about five seconds before they started again. They lasted for little over an hour. I ate my lunch to see if I could relieve the nausea and it did, and they haven't came back since, only the usual period pains in my lower back. 
I'm 36+4, is this normal? Was it braxton hicks? 
I've only ever had cramping this bad once, and that was a few weeks ago. 
Help?