hi ihad aparty in one of the club 3 to 4 day back, i was so drunk that i was unable to stand as my drink i suppose was spiked, i was wearing a full suit that night ,next morning i happened to notice a needle scratch on my right arm which was 2to 3 cm in length not very deep , but mild superfical scratch i am scared whether i will contract hiv from this needle like scratch , what precautions should i take pl help