tbh, given that you didn't know you were pg, nor do you want to be pg either, you are most likely to be suffering from shock. what happened and what you saw can't have been pleasant for you to have gone through
i would imagine the blood test will show the pg hormone levels to be quite low, which would probably confirm a m/c. they may want to either re-test in a couple of days to see if it goes up or down or scan to check everything has gone.
i've had 2 m/c's, it can take up to a month for all the hormone to be out of your system, have you asked anyone what you should do about taking the pill, carry on as normal or give your body a rest maybe for a month or so?