I am 5 weeks pregnant & having a tooth decay
Don't worry. Safety apron used. Should be ok.
I welcome you to HCM virtual clinic.
I have understood your concern and I will suggest you the best possible treatment options.
First of all do not panic.
As mentioned in your question, that you had been given protective lead apron , you should not worry.
Secondly, usually dental X rays are in the upper part of the body and travelling only through your chick..
Your concern about baby's safety is absolutely right, but in my opinion, safety precautions have been already observed. So you need not worry.
I hope this answer helps you.
Please feel free to communicate with me again.
Dr. Purushottam Neurgaonkar