Do I have to take an X-ray even if my daughter still has secretions?

Hello, My 16 month old daughter was hospitalized with pneumonia in December. I had to go back to the hospital to do a follow up x-ray at a time when she was fine but she still coughs a little at night since then and has secretions. I'm wondering if I should wait until she's not coughing at all or if I should still go for the x-ray just in case?