Try not to worry too much, I know it's hard.
I had some dental x-rays during my first pregnancy, must have been about 8 weeks pregnant, but didn't know at that point.
Baby was born perfectly fine.
I spoke with my dentist about it about a year later and he said it was nothing to worry about/perfectly safe.
More recently, was around 7 weeks pregnant with baby no.2 (3rd pregnancy) and was having a dental check up, dentist wanted to do some x-rays.
As soon as I told him I was pregnant, straight away he said that we could leave it for now as they were just routine, not for a specific dental problem.
I was happy to leave it and I guess, from a clinical perspective, a doctor/dentist would rather avoid taking that risk, unless there was an emergency/real need for one e.g. fractured bones etc.