Oil Change: Right Motor Oil, Wrong Oil Filter?

I drive a 2001 Ford Taurus SE, I [attempted] to do my oil change today.

I have been using Royal Purple 20-400 (oil filter) AND Royal Purple 5W-20 synthetic oil.

After I drained the oil from the oil pan into the catch pan, I realized that the new oil filter that I purchased was the wrong one. As stated above, I was supposed to use Royal Purple 20-400 with my car, the one I purchased was 20-820. I just ended up leaving the old one on there, though poured in the new synthetic oil. I have been approximately 12K miles on this oil filter, however, the highest potential is 14K.

That said, when I receive the new 20-400 in two days, could I just use the oil that I just recently put into my car?

What effect(s) (if any) could this have on my vehicle? Is there an that I should be worried about given this potential scenario?

Won't hurt a thing to run the old filter a couple days. Oil filters have an internal bypass valve, so that if it ever clogs up with crud. The oil will still flow through the engine.

When you get the new filter, spin it on and top off the oil. No problem.

One thing though. I wouldn't run that many miles between changes. Oil is changed because of contamination, NOT because it's worn out, and synthetic gets contaminated just as fast as regular dino oil.

You left about 1/2 quart of old, dirty oil in by leaving the old filter on. You should have at least removed it and dumped the old oil out.
Royal Purple is mostly a scam purchased by people who believe their ridiculous advertising. Their expertise is in racing oil, which has little to do with street oil.

Some idiotic engine owner's manuals require ONLY changing the oil filter every other oil change. You should have probably went and got the correct filter before starting the engine. If you dumped the old oil out of the filter, it should be OK. If you don't have a lot of wear in your engine, there probably isn't anything to filter out of the oil anyhow.