hello sir, am a college student from india. Yesterday i went to watch a movie in theatre.i was fine until i came home back. I felt something pricking behind my thy. But there was nothing actually. No identity of a pin prick or something like that. But some kid of pricking feeling that i have till now. Its a feeling that a person has after getting injected by a doctor. But there are no signs not even a red mark in that area. My question is was i actually affected by a pin that is very small in diameter that it leaves no sign but could transmit blood into me or it is simply some king of skin allergy that i am imagining to be a pin prick attack? Even if it is some alergy how can i get the pricking feeling without even some signs at the region of infection? please help me...