Was I jabbed by a needle?

I have been worrying for the last week that I was...I sat on a public chair and felt a sharpish pain in my backside. I didnt see a needle but am now convinced one must have been hidden in the chair! My husband looked for a puncture wound and couldnt see one but its now been 7 days and I have a painful pimple where I belive i felt the sharp pain and I have also come down with a horrible virus - sore throat, fever, tiredness, lack of appetite and feeling sick etc. Have I caught something???? Could it have been an infected needle I sat on?