Hi.
I've gone through your query and I can understand your 
anxiety. 
Brownish discharge in your (14years) age group could be of ovulation or a sign of your upcoming periods. 
Hot flashes are common during Premenstrual & menstrual phases, which is due to the 
hormonal changes during the cycle. Also 
Stress & anxiety are key factors which causes hot flashes. 
I advice you, 
* To do 
YOGA * Relaxation exercises to get out of stress 
* Have salt restricted diet 
* Avoid caffeine and alcohol
* even after periods if you get hot flashes, check your TFT ( 
thyroid function test) 
Hope I have answered your query. Let me know if I can assist you further. Take care. 
Regards, 
Dr. Yogapriya V, General and family physician.