Earlier today a buddy of mine changed my oil. He had me pull the car onto a ramp, and after he drained the oil and changed the filter he had me start the car and back down the ramp, and I did because I didn't realize he didnt put the new oil in it yet. It took maybe 30 seconds total, maybe a little less. I've driven it a couple of miles since then without any odd noises or anything. Is it likely that ive done some sort of serious damage to the engine?