My dad did something!=(?

it happened 3 years ago....

when i was 9 my dad did something bad...
when my mom's not home..at night my dad did somthing bad like touch me under my pants...=( me nd my sis has the same roomm but she cant notice...sometimes he kiss my b**bs nd stuff..he thinks that i did not noticed him ..after that night or after that day(i forgot) i started to hav my period (i had a period when i was 9) my mom know nothing bout it he diid it oncewhen i was nine then he did it once again when i was 10.. nd again when i was 11 (im 12 right now) i wanna tell anyone but..im too scared to tell anyone but still my dad dnt know tht i noticed it...plshelp no bad answer pls

this is REALLY bad, tell your mom as soon as you see her!!! NOW!