I dont get it why is it not regular yet? girls?

i started for 2 yrs since i was 11, now im 13 but soon it will be three yrs, cause im turing 14 in march, an right now 6days late and never been late well idk really cause this first time i put on calendar Just for ur info i jsut started putting on calendar cause i diddnt want mom to no im shy bout this stuff, well this will be my 2n period calendar time last time it was exactly 28days but now im 6 days late, wats going on, im a virgin