hi, it's good that you realized what was going on! i also lost my period when i lost weight. even after gaining weight back, it still took some time for my period to come back. so if you're eating right and not putting too much stress on your body from extreme work outs, then i am sure it will come back very soon considering it wasn't gone for long.
Firstly, congratulations on realising and catching your eating disorder before it took control of your life! :D
For a woman to get regular periods, their body fat percentage needs to be at least 15%.
Scales are usually not very trustworthy when it comes to anything other than weight (though even that needs to be questioned occasionally). What other method did you use to calculate the 17% body fat?
It may take a few months for periods to return as the body prioritises general health and well-being over reproduction. I would wait for a bit longer and continue with the recovery diet, as it seems to be working.
I have just recently recovered from anorexia, ive just been discharged about a month now. my lowest bmi was 16 which is dreadfully low! I was in denial about it infact i didnt even know i had an eating disorder! Its great. that you noticed as soon as you did before it got much worse. My period was away for ages when i was a really. low bmi but it came back once i had put on a few pounds, i think i was only abput about 43 kg when my periods returned but it depends with every person as everyone's body is different. and may require a certain weight for your periods to work. I was so pleased that mine came back as that is a sign that you are getting healthy again! And no you can not really recover through gaining weight but it does help, however you need to go through therapy such as cognitive behavioural therapy and maybe a body image programme, this is what i did. This is in order to reduce the anorexic thoughts and get your thinking back to normal as anorexia is a mental illness. So best of luck to you, i hope they can come back and that you can continue to gain weight and become a healthy bmi again. Just remember to think positive, it is scary and hard at first but it really pays off! You will be so much happier! :)