Technically there is only a week that your visa has been approved. Usually this process can take two to four weeks depending on the country. You are fine, seat back and enjoy the remaining time in your country.
1. No, your fiancé does not need to call the NVC. You just go to medical and they will diagnose it and you will be able to get treatment or they can recommend treatment at another hospital.
2. IF you are diagnosed with TB from SLEC then your petition does not expire it will simply be put on hold until your treatment is complete.
3. You can undergo treatment at any hospital or clinic you like where you live as long as you get treatment.
