Strong rectal odor and now i just experienced a sharp pain that i felt in my lower abdomen all the way to my rectum, what could that mean ?

A few possibilities: Infection is what you should think of u are sexually active. Rectal odor and pain may relate to std e.g. Herpes and/or gonorrhea. Usually, there should be vaginal symptoms if this is the case. Other possibilities include inflammatory bowel disease, rectal fissure, or hemorrhoids. Need to see your doc for appropriate management.