Women's Health Medicines

So first off there is no way I'm pregnant. I am 19 and am starting to worry about "irregularity." I have been getting periods off and on (mainly off) for years now. Sometimes though I'll go 11 months without one, and then when it finally comes I am practically doubled over in pain. Does anyone have any ideas? Is this normal?
I am a typical weight, I excercise, I eat healthily and I am not super stressed.

Kayla, it is not normal. You need to check for hormones (e.g prolactin levels). You can make test for infections - some of them may cause irregularity. It looks like hormonal problem. Many girls face such problem in ages 12-18. It is a good idea to make blood test for hormones.