You Need To Stop Stressing Because it Doesn't Do Any Good And You Can't Go Back And Change It Now.
I Had Dental Xrays While Pregnant And My Daughter Is Perfectly fine.
I was also xrayed at the dentist at 24weeks and they double gowned me. You don't need to worry. Your baby will be just fine!! :)
Trust your doctor and try not to stress. If he said it's fine, then it is.