Once every week or two I get this terrible pain in my back and stomach right under my breasts , I can't sit or stand up, they only thing to sort of help is to get on my hands and knees. And my bp gets really high. Then after 5 mins or so it completely stops and my bp lowers into the normal range. I haven't talked to my doctor about it because it doesn't last long and it only happened 4 times with weeks in between. Could it be Braxton hicks?