I've heard there is still debate out on whether Xrays, for dental reasons, can harm an unborn baby. I'm sure if you're just there for a checkup and opt out of Xrays, you'll be fine. When I was pregnant with my daughter, I put my hand through glass and slit my thumb wide open.
I had to get xrays at the ER and they just put two really heavy lead vests on me and then a lead blanket on top of that to protect the baby.
I am in my 2nd.. almost 3rd
I work in a dental office(im at work right now) and Our dentist say not to come intill after your your 1st trim.