The telltale sign of thrush (oral candidiasis) is that its a white patch and can be wiped away easily. You may want to see your dentist to get it checked out and if so, yes, they can prescribe an anti-fungal to remove it as HHayley stated.
It is a possibility that you may have the yeast infection, called thrush. It can be caused by taking certain medicines, such as antibiotics. It can also be easily treated when seen by a doctor and given a specific mouthwash to use x times a day. Hope this helps!