When you bought the options, they were worth $33, right? So that right there invalidates the statement you made about the options being worthless until they hit the strike price.
Your positive PnL is the result of the probability of these options becoming worth something increasing, simply put. Consider reading Natenberg or something like that before you start swinging 100s of SPY contracts around--not trying to be a dick, just want to help. Congrats on a good first trade.