LOL Yes, that is probably it!
I did my test in a flurry of nervous panic.
We were at the inlaws for the weekend, and I only started suspecting that morning. Me and DB went and bought the test, but decided to wait until Monday morning to take it (cant remember why).
We were watching TV and I'd had massive amounts of diet coke and needed the loo, so went upstairs and suddenly decided to take the test, but was actually bursting to go, so was pacing back and forth in the bathroom desperately holding it while trying to skim read the instructions!
Thinking "sod it, it's peeing on a stick", I did the test, then read that I was supposed to leave it for 3 minutes before looking, and had a stupid moment of irrational panic as I had already looked!! I got two stripes almost instantly, but then stood for three minutes with my back turned knowing I was pregnant but being utterly confused. "Must wait for 3 minutes!"
My boyfriend completely guessed what I was up to and was outside when I was done. Then we had to come up with some excuse to "go for a walk".
Being a computer nerd, I kept wondering if I'd somehow "saved my progress" before hand, in case I wanted to go back and undo. Really weird. As it was I didn't want to undo, so all is well. 
Anyone else with a slightly irrational reaction to the news?