 [ Symptoms ] hi my blood group is o  and i sucked few drops of a+ blood from my girl friends cut is this harmful for me  hi my girl friend accidentally got a small cut on her hand and i sucked that blood immediately it was just a few drops my blood group is o  and her blood group is a+ is this harmful for me if so what should i do now please do help me out with this thanks [ Disease ] no this would not likely be harmful assuming your girlfriend does not have any blood borne diseases like hepatitis sucking blood really not a safe practice even for vampires so i would caution you from doing this again unless of course you are a vampire