45 days delayed of my menstruation but i feel that i have a menstruation symptoms

hello everybody i need some help, if its true this is my first time to have a baby and i don't know what i am doing......i am 45 days delayed of my menstruation but i feel that i have a menstruation symptoms.....my breast aches, back aches and last night i suffer from cramps....am i pregnant? my last menstruation was last nov. 5 2012.....i need some advices....tnx