Strange bump

I was in the shower this morning (Yay! I don't stink!) and as I was washing my hair it felt like there was a bruise on the back of my head. There was a goosegg of a bump back there and it hurt! It feels like its growing.

So I went to work and told H and D that my head hurt. Like I was clocked in the noggin while I was asleep. So they ask, "Well, were you?"
"Not that I can remember", I say.

So do you think you can get a tumor and it can grow overnight????

So H suggests that its a spider bite.
D suggests that maybe a spider laid eggs in my head.

Thank god I have friends.