As you have a prescription for the hydrocodone you might be okay, depending on how in depth the test is.
Oxycodone and hydrocodone are both opiates so should show up the same. You have a prescription to prove that use is legitimate so no problem there.
However, the problem is that it will show as abuse as you will have a very high level of the drugs in your system.
As you have been in a pain clinic though, and these are indeed painkillers, again, you may be able to talk your way out of that one.
Hopefully, if you tell them that the pain was really bad, and you took probably more than you should have done, they will believe you.
The Oxycodone (Roxy) will stay in your system and be detectable for 3 - 4 days so you really don't have time to get this out.
Normally you could try drinking water and sweating it out but 14 hours is too short a time for it to do any good unfortunately.
Hopefully, the prescription will cover up for the Roxy in your system too - good luck!