Your doctors consulted with each other and worked together. They wouldn't have done the surgery if the risk were greater than the benefits. You have no reason to "freak out." Your baby will only have problems if you don't watch your stress and anxiety levels in order to keep your blood pressure down.
Women get dental procedures done while pregnant all the time. Please try not to worry. You did the right thing.
EDIT: The X-Ray would have been on your mouth, not your belly, and your entire midsection would have been covered by a lead blanket to protect you and the baby. They do that even when you're not pregnant. You HAVE to stop worrying about this. It's not productive worrying. If you're this anxious over something this minor and the baby isn't even here yet how are you going to handle truly serious situations when the baby comes?