I have a hard stomach and pain low down on the right hand side any idea to what this could be?

Go to an ER: Right lower abdominal pain is classic appendix pain, however, in a female, especially one with your history there could be other causes such as ovarian cysts or ectopic pregnancy. If the pain is severe , especially is associated with nausea or you might be pregnant, i would suggest you go to an er where they will examine you, look at your white blood count, check for uti, pregnancy, prob ct scan.