Dark oval object photographed over San Francisco

I was cleaning the lens of my camera. I was trying to clean off a very small smudge mark on the lense, so I took my camera outside, pointed it straight up into the clear blue sky where there was nothing , and snapped 2 random shots, 2 seconds apart, in the exact same place in the sky so I could then take my camera back into my office and look at the photographs to see if the smudge marks were gone. They were, but in looking closely at the photographs to see if the smudge was gone, I noticed a small dark speck at the top of the first photo. This is a 6 million pixel high-res digital camera and I zoomed in on the object. Upon doing so, It became clear that this was some kind of flying object, sort of an oval in shape, and by the amount of deep zooming I did, appeared to be very large. The second photo showed nothing but empty space. I have the photo if anyone wants a copy, your guess is as good as mine as to what this thing was. I have also emailed this photograph to [email protected]