Real Contractions?

I have been having painful cramps that start at the top of my bump and feel like they radiate to my vagina. I also have a good amount of back pain following the cramps. But not at the same time. They last a little short of one minute. And have been about every 15 minutes or so The top above my belly button gets very hard but i have some fat on my belly at the bottom and can not tell if that is getting hard also. They are bearable but definitely hurt. Is this the start of labor or just painful Braxton hicks? I have a week and a half before I have a scheduled C-section