Re: dentist visit
I've been to the dentist during this pregnancy & got a full updated set of X-rays. My doctor said it was absolutely fine to get the X-rays. My denist was absolutely fine with giving the X-rays.
Since you haven't been in several years, they'll surely want to X-Ray you. They have a vest you have to wear. As long as you're wearing it, you're fine.
If there's any dental work that required meds or putting you to sleep, you'd better check with your doctor.