If the medical imaging is clinically warranted, there is no need to worry. The amount of radiation from an x-ray is very small. Still, it is important to keep the radiation amount as low as possible. A common question parents often ask is: How much radiation is used in these exams? Rather than answering the question in terms of units of radiation dose such as mSv which means nothing to the average layperson, a better way to think about it is to compare it to background radiation which we are all exposed to in our daily lives from the sun and natural environment. People living in the mountains or flying in planes are exposed to higher amounts of radiation than those living near sea level. The amount of radiation from 1 adult chest x-ray (0.1 mSv) is about the same as 10 days of natural background radiation that we are all exposed to as part of our daily living. The amount of radiation from 1 adult spine x-ray (1.5 mSv) is about the same as 6 months of natural background radiation that we are all exposed to as part of our daily living. The amount of radiation from 1 adult dental x-ray (0.005 mSv) is about the same as 1 day of natural background radiation that we are all exposed to as part of our daily living.
Source: https://www.radiologyinfo.org/en/info.cfm?pg=safety-xray
X-Rays for Children: What Parents Should Know About Radiation Protection in Medical Imaging
For more info: https://www.imagegently.org/Portals/6/Parents/Im_Gently_XRAY_2pg_English.pdf