What does BH feel like?

I'm 35 weeks and 5 days, and yesterday while I was at work (I'm a server, but I had only been there 45 minutes, so I wasn't on my feet all day or anything) I started getting these cramps...I've had cramps before, ones that you might have gotten a day or two before your period, tiny little ones. But yesterday, it just came at once and I felt horrible. I didn't feel good, the cramps were way worse than before. I almost decided to go home, but finally it stopped and I felt 100% better. I drink tons and tons of water, so I don't think I was dehydrated. Do you think it was like growing cramps or BH? I'm a FTM so I have never been through all this.