38 weeks. Could I possibly be experiencing labor pain.

I've been having sharp pains in my back that come and go and very few sharps pains down low. Mostly in my back that I can time for 3-6 minutes and we're about 10-18 minutes apart. They started last night for about two hours and then stopped for no reason. They just started up again about an hour ago but now they are more frequent. Should I be worried? Should I head to the hospital? Could this be back labor? This is my first pregnancy and I need opinions.