good news
I went to the doctor, explained everything to her
she said i have secondary amenhorrea. basically the fact that i had a period at all in the first place means that my reproductive organs all exist (lol) and i am not in any danger
she is very sure that my absence of a period is due to low hormone levels. she could have given me a hormone test, but didnt see how that would help (it would only tell her what she knew)
so she said all i have to do is wait. she said my running might play a part in keeping it away though (but i am fine with that! lol)
she said i could go on the pill, but like some of you mentioned, that would only give me "artificial periods" which would serve no purpose
the best part is that i am completely healthy, and my bones are fine because i exercise and i have a good diet