Well, if you have never had a cold sore before, then you may wish to have a swab test done but the Valtrex that you have taken may well interfere with the results of the swab test. Have you recently had a sexual contact you are concerned about? It sounds pretty classic to me but the clinician that saw you would know best.
And yes, you may need more Valtrex. is there a refill associated with your prescription?