It is very common for travellers to come for a week of vacation and end up staying for a longer period. Cabarete is full of people who loved it so much that they end up statying a month, a season or years at a time. So what happens if you over stay your 3 week visa? Not a whole bunch really, just a fine at the airport when you eventually leave. Fines vary from 800RD for a short overstay to 17,000RD for a long one. For more information please visit the Dominican Immigration website