Evening primrose oil

I have heard a little bit about this and would like to try it and my hope is that it could maybe help with getting my periods back on track ever since I have been off of birth control (2years ago) I have missed every third one this time I finally didn't but I still have majorly long cycles they are ranging 26 days to 86 days so I'm hoping this helps but willing to try anything before I head to the doctor to see if I am broken lol but what have you heard and/or has done for you