Contractions? A little worried...

AshEliz

I'm a FTM so I don't really know if this is normal or not. I am 31 weeks and last night I was woken up last night by what seemed to be really different (i.e. painful) contractions. I have had BH since about week 20 but this was way different. My entire belly seized together painfully and then I would get a shooting pain down my left abdomen. It would last for a minute or two then stop so I could fall back asleep. This happened 5-6 times with no regularity. Is this just stronger BH or should I be concerned? I feel like I did 1000 sit ups this morning but nothing else is different and I have been staying well hydrated. Should I be worried or is this normal? Thanks!