I've never heard about pregnant women having to avoid people who had a recent x-ray. According to the Mayo Clinic: "The possibility of an X-ray during pregnancy causing harm to a fetus is very small. Generally, the benefits of the information from an X-ray outweigh the risks."

Source: https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/expert-answers/x-ray-during-pregnancy/faq-20058264