symptoms of amenorrhea/pregnancy?

so I was having a friendly chat [haha] with a friend about amenorrhea.. she said her mother'd had it, and that the symptoms were very similar to those of pregnancy.. frequent urination, fatigue, irritability, etc. I was wondering how true this is. I haven't had my period since July [and I think it's athletic amenorrhea; I run a lot] and have experienced some of these symptoms. I'm DEFINITELY not pregnant, haha.. I just wanted to know if there was any truth to this. Anyone?

I have experienced those symptoms and I took a pregnancy test, just to make sure.  I wasn't pregnant but it seems that it does make sense that one would feel that way.  I've read that low bodyfat levels can influence hormone levels, so the experience that I've had reinforces that train of thought. 

Maybe a little Internet search will help.  Medline is a good site.

I dont quite know the answer to this but I would have to say that those symptoms definatly apply to me since I stopped getting my period a while ago.  Maybe they are the same symptoms as pregranacy?  If you find out, please let me know!