My OCD makes me so paranoid about needles....?

I suffer with various symptoms of OCD and am on the waiting list to begin counselling for it. One of the scariest symptoms I keep getting is a paranoia of getting jabbed with hypodermic needles in public. I get convinced I have felt something sharp prick me and that it was a needle that was planted there in order to harm someone and make them sick. Like yesterday, we were looking at sofa's in a shop and when I sat on one, I felt something sharp on my backside and even though I didn't SEE a needle there, I have since been convinced it must have been a needle planted in between the cushions. I have been inconsolable about this even though my husband has been trying to convince me there couldn't have been anything there cus its so unlikely anyone would do that - I wont believe him or listen to him because I think he isn't taking me seriously as he knows i have OCD. I cant stop worrying that I WAS jabbed by something. I hate having OCD because you don't know if this IS a symptom of COD or if there actually WAS something there!!!!!!!! Its really upsetting me. Any HELPFUL answers appreciated :(