Female Question...

So, I've only had one period. ever... three years ago. (was smack in the middle of the BMI range)

I ended up increasing exercise (figure skating) to 24 hours a week, for about a year and didn't have a period at all during that time... I still discharged though (at least... I think I discharged).

Lost weight, quite figure skating, and regained weight to where I am now... about a 17.8 BMI. I exercise around 8 hours a week...

Throughout this time, I've still had discharge (sorry if too TMI), at least, I think it's discharge... it comes pretty much 24/7 (though every once in a while a lot comes) and it kinda sticky... and has kinda yellow tint to it...

My lower back and pelvic region kinda hurts on and off (tylenol doesn't seem to help), but I think that's more from the running I do...

I've seen a doctor, and have had blood work done (about three months ago... but it's the same as it was a year or two ago, so I doubt anything has changed) and everything is normal.

Am I still at risk for osteoperosis? 

You need to see a new doctor.  Yellow discard could be a sign of a bacterial or viral infection. 

Take care of yourself.  Too much exercise can be harmful.  Please go see a new doctor.  An OB/GYN.

Does your discharge emit a pungent smell? Even if it does not, you should still see a doctor regularly because missing periods is very dangerous.

So your BMI now is 17.8, or is that what it was?

I would go see an OB/GYN. Have you ever gone before?  It could be no big deal or it could be something really serious. I would go just to be on the safe side, it can't do any harm.

I would definitely see a doctor, OB/GYN.  You may have a yeast infection or something else going on.  Also, it sounds as if you are underweight and there's a good chance that is the reason for not getting your period.

Chirpp: you are

-underweight
-undereating
-extremely active

Three main causes of amenorhea, and you've got all of 'em.

Personally, I started my period around the age of 12 and have never been regular. Two years ago my period stopped for 6 months but I had an eating disorder. My BMI never got below 18 though...Even now at a healthy weight, doing everything 'normally' I don't get my period sometimes for months and months (5, 6..) I am not sure what your diagnosis would be, and I agree seeing a doctor would be the best way to go, but not every woman has a 'monthly' period. And discharge is normal usually, but again only your physician or OB/GYN could tell you for sure.