Missed period 2 months in a row.

So I have missed my period 2 months in a row. I am not pregnant because I took like 5 test and they were all negative. I am experiencing mini sharp pains in my pelvic area. I havnt lost any weight so I dont think its that. Im wondering if it is stress because one of my rapist from 3 years ago keeps coming to my work. This has happened 4 or 5 times. I have a trigger each time and its been difficult to recover from them. I am getting help for that btw do you think that this could explain my missed peirods? Or could it be something else? Any suggestions?