I received oral sex from a woman am a man. i had this barely visible sore which is never been bleeding on my penis.will this pose a risk for hiv?

Small, but yes!: Anytime you have unprotected sex (oral or otherwise) with a person you do not know, or know well and know to be disease free), you risk contracting a sexually transmitted disease. While HIV is rarely contracted with one time exposure by any route, the chance is not zero. Also, gonorrhea is a very good possibility as is herpes (whether type 1 or type 2). So get checked & repeat testing per MD.