X-rays at the dentist while pregnant..?

I'm currently 16w3d, and my front tooth cracked due to dental work I had done about 3 months ago. They did a filling in the back of the tooth and it was so deep that it ended up cracking the front of my tooth. It took until now that a chunk finally fell out.. They said they need to do a route canal eventually and something about a cap; they just filled and fixed it for now though. They told me I needed a X-ray done, I was hesitant but they insisted and told me it was perfectly safe for the baby and I. They only took ONE X-ray, they put two aprons on me and put it on the lowest radiation and told me everything will be fine. I'm kind of freaking out and had a tummy ache after.. (probably my mind and anxiety).. I'm so paranoid. Can someone reassure me that everything will be ok and give me positive stories that relate? I can really use it because I'm so scared and nervous to lose my baby.. I took the dentists word though. Thank you!