Dude... you're gonna lose like... 4 dollars. I wouldn't worry.
Reusing motor oil is pretty low on the "Smart things to do with your car" list...
How long have you had this oil, anyways?
You can drive a little bit. Just don't think it's OK to drive everywhere.
Did you put this oil in, or was it some people at a oil change station?
ALSO: Check your oil again... did you take out and wipe the dipstick BEFORE putting it back in to take the reading?