What Are The Long Term Effects Of Irregular Periods?

Hi. I am 23 and started running a lot when I was 15 years old. I had started periods about age 12 or 13, as normal. After I began running, they became irregular and I then had the longest gap ever- 15 months. I run long distances, but not over 40 miles per a week... When I tried running in 50s, I got injured. Now, at 23, and consistently exercising about the same amount, and I still am irregular. Occasionally, it will be like 6 weeks apart but that is very rare... normally, I won't get it for 3 or 4 month spans. (now- I last had one in February!) I write them all down in my agenda book to keep track of them. I am concerned about what this will do to my health, through my future in life- when I want to have a child in a few years, my bone strength when I get older, etc. Should I see my doctor about this?