I Went For My Medical Check For Yearly Rehiring. I

I went for my medical check for yearly rehiring. I am 66 years old. My dr asked me to take Augmentin 625mg antibiotic 2 times a day for 5 day because my chest xray is not satisfactory. I am asked to return in 6 weeks for another xray. In the meantime, my employer cannot rehire me. Is this common practise ? Please advise.

Thank you.
KH Tan