What do your Braxton Hicks feel like?

Can anyone explain to me what you are experiencing with Braxton Hicks. I have some cramping in my lower belly, under my belly button along the entire front area. They come and go. I have been noticing it over the past couple of hours. Uncomfortable for sure but not screaming painful. My entire belly (low and high) is tighter today too. Is this Braxton Hicks? How would I know if it’s pre-term real labor? I’m 31 weeks tomorrow.