I WAS BITTEN BY A SPIDER ABOUT TWO MONTHS AGO.

I WAS BITTEN BY A SPIDER ABOUT TWO MONTHS AGO. I DID NOT SEE IT AND NOW I HAVE A SORE ON MY THUMB STILL THAT HAS BEGUN TO FORM WHITEHEADS. THIS DIDN'T CONCERN ME UNTILL THE WHITEHEADS BEGAN TO MOVE TO DIFFERENT PARTS OF MY THUMB. SHOULD I BE CONCERNED? AND I HAVE BEEN PUSHING THE FLUID OUT, IS THIS OKAY?