What to do if I got punched in d mouth&i have braces on, my 4 front teeth got slighly loose but they don't hurt my dentist said I will be ok should I worry?

A blessing or a curs. Injuries to the head and mouth occur during orthodontic treatment. Braces may prevent your teeth from being knocked out. The curse because your lips generally get more trauma and swelling than if you didn’t have them. If you are under dental care is nothing to worry. Life goes on. Good luck.
Good news. Good news is braces probably prevented teeth from being knocked out. See Orhodontist immediately to check appliance integrity (bent wires can cause incorrect tooth movement). Small chance teeth will become devitalized. Take Aspirin or Advil (ibuprofen) for 2-3 days to minimize swelling. If symptoms persist check with both your Dentist and your Orthodontic Specialist.
It depends. It really depends on how loose they are. If your dentist knows about managing traumatic injuries to your teeth His/hers advice may be absolutely correct. If you have any question you should see and Oral & Maxillofacial Surgeon or Endodontist 9Specialist in Root Canals).