Red patches that come and go and change places in the roof of my mouth- what can it be? my dentist she said to wait 2 weeks- couldnt tell what it is..

Red patches ?: It could be a number of things. We can't always tell what it is just by looking. In those cases, we wait two weeks to see if it goes away. If it does, it usually doesn't matter what it was as long as it does not return. In order to know for sure what it is, we would have to take a biopsy or surface scraping to find out. We try to avoid that unless necessary.

2nd opinion: If your Dentist isn't sure you would be wise to seek a second opinion. You would want to see an Oral and Maxillofacial Surgeon, an Oral Medicine Specialist, or an Oral Pathology Specialist.