Did you get this egg from someone else, to incubate? If so, you might ask them what it could be.
It might be a Coturnix double yoker - they do sometimes lay these, and compared with a CPQ egg they would look very large. Don't know why this would have got in with a batch of COQ eggs though, if you were expecting a pure batch from a breeder.
Or of course, just pop it in the inci and we shall all be interested in what emerges, though if its a double yoljker its not very likely to hatch.
How are the previous hatch getting on?