help me! im 13 years of age for the past 3 days i have had extream lower back pains, and every time i stand up i feel like i have to purge and pass out, my mom left me when i was little and i have been living with my dad ever since, im not for sure if this is period problems or what but every time i tell my dad he says that its my period  but i have never felt like this before on my period :(