BEFORE GOING TO THE SECOND DENTIST.....GET THOSE XRAYS FROM THE FIRST DENTIST. This way, you won't have to pay for additional xrays and the new dentist can tell you if there is anything on them.,,.,.supposedly that is what the first dentist used to determine if you had cavities...they should be visible...I would also make sure that the receptionist had the right patient and records when talking to you....but definitely get those xrays.
Best of luck.