I am 28w5d and have been feeling this odd sensation towards the top of my uterus. It feels like my baby is taking her body and pushing as hard as she can against that area, or like the tightening feeling of a charlie horse before it gets really painful. But it is only at the top of my bump, it doesn't spread lower. I don't feel them often, but when I do they last only 30 seconds and go away when I twist or move. Are the feelings I'm having Braxton Hicks?