I have Menstrual Problem

i am 20 years old.. never been through Premarital Sex or never have intercourse..i have a regular mestrual cycle before when i was 17-18 years old but when months past I missed my period for 6 months (thats year 2009) and after 6 months my period got back to its regular cycle and i reached 19 years old (my bday is march 27, 2010) until July 2010 my period is normal but when its August 2010 its back to its abnormal way and missed my period until now (its already September 2011 so it means i missed my period for 1 year and 1 month or maybe 2 months because its almost October 2011) but am not pregnant and i never been gone to a GYNECOLOGIST because im afraid on what my the result be but i consult a friend of mine who is an ONCOLOGIST Doctor and she said that i should see an OB-GYN.. what am i gonna do? should i go see an OB-GYN (im afraid) or not? Can someone help me pls... Give me your feedbacks or answer pls.. I REALLY BADLY NEEDED HELP or SOME ADVICES PLS!!!! HELP ME!!!