Figuring it out

I'm 36 weeks today. I had very mild contractions from 8:30ish this morning until 1ish one every 20-30 minutes. I decided to go for a walk to see if they stopped and they were more frequent and a little more intense. One every 10 minutes lasting a few (10-15) seconds. When I got home i grabbed a small glass of juice to get my blood sugar back up and they stopped. I didn't have anything for almost 3 hours and then I was just vacuuming and they have started again. I don't want to call the midwives yet since they aren't 5-1-1 but should I be worried or is this just Braxton Hicks? Thanks