Rated PG 17- Painful sex but not in the way youd think

(i have a smashed phone screen so I apologize for bad spelling) 
​Sex itself doesnt hurt.   My private areas dont hurt during sex but sometimes the left side of my stomach does.  It feels like something is jammimg into things and twisting things.  It used to happen once every 8 months or so but now its more and more constant.  Especially if im on top.   My breasts have been really sore as well.  Please, any insite at all??