Thrush does seem the most likely explanation. As you have had unprotected sex though, I think you should test for the usual suspects for your safety and that of future partners. Hence look for gon/chlam/trich at two weeks, then HIV, Hep A/B/C, HSV 1/2 and syphilis at 12 weeks to minimise the number of times you present yourself for testing and observing windows.