Braxton Hicks or however you spell it question..s...

Okay so i am 31 weeks 1day pregnant with twins and since yesterday my belly has been rock hard.
If i lay on a bunch of pillows and on my back it seems to soften up a little but once i sit up or stand it goes right back to being as hard as it was ....
I honestly don't know what braxton hicks (sorry if misspelled) feel like since this is my first pregnancy, though i do know that they don'tl last that long and my belly has been super hard since 5:30pm yesterday and today it's not any better .
Can someone please explain what braxton hicks feel like or if you have felt the same feeling let me know what it was or is if your going through it.

Definitely sounds like contractions. I would be calling your doc to let them know and time them!

I would just stay laying down and call your doctor. Also time them.