Am i close to my period??????

iv been having mood swings a lot. discharge always comes! it never stops? my back hurts but i wear a belt when i play softball is that the problem. also i get like kinda pains in the lower part like farting pains... its weird. iv been dizzy lately but its like on and off i am 12 i do have im a A to a B everyones getting it! my friend said when a woman has there period and when theres ends u get it is that true ! help me please