Accidentally found some ulcers on my son's molars under a film. I'm cr…

Accidentally found some ulcers on my son's molars under a film. I'm crying because it could be something like that. Paid clinics don't work tomorrow, and those that do have no appointments. We'll go to the hospital in the morning. There is no fever, he behaves actively, if not for the accident when he sneezed on the street and opened his mouth wide - I wouldn't even recognize it. Hands reach into his mouth sometimes, and sometimes at night in tears wakes up, but thought about teeth. Maybe someone had this? How were they treated? I'm afraid of local doctors because they almost interrupted my pregnancy and a dentist put a stomatitis on my son - she didn't change the