ok now I am panicking a bit more....Didn't know I could register for a GP. Thought that was after the Visa approval...No on DVLA because we were told I was good on my DL for 12 months and that info is also coming from 2 of his relatives who works at the DVLA and no...I have nothing...OMG!!! 
You can register with a GP at any time. The only difference is that if you need treatment during your fiancé visa, you have to pay for it (and show health insurance).
I would apply for a provisional licence and get started on working towards getting your UK driving licence ASAP.
While you can legally drive on your US licence for 12 months, if you haven’t got your full UK licence when the 12 months are up, you can no longer legally drive... and until you get the UK licence, you will be treated as a brand new learner driver (L plates displayed on the car, and you must be accompanied at all times by someone over 21 who has held a full UK licence for at least 3 years.
It can take several months to pass all the tests, and it’s a good idea to take some driving lessons to learn how to pass the test.
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