Braxten Hicks?

Hey just wondering if this is normal for anyone else. I am 33 weeks and I usually get bh after I go to the bathroom or after I take like a 10 minute walk. Today I have been getting major cramping sessions every couple of hours. The sessions last like 10 minutes each. I have had about 4 or 5 today. 2 of which were just out of the blue, I wasn't doing anything but sitting there. Are these common bh or should I be worried?