XRay during pregnancy

Good evening everyone,

I took a pregnancy test on Monday and it said negative. I made an appointment because I started having severe pain on my tailbone area. I went for an X-ray today and they asked me if I was pregnant, I told them no since I took a test on Monday. Something didn't sit right so I took another test when I got home. It's positive and I'm so scared because I just exposed my stomach to Radiation. She took 3 pictures. Has anyone experienced anything like this? Please send me feedback.