See I should read more carefully :) I missed that you posted your med...to clarify for those who don't know azythromyocin is the med z-pack :)
When I had pneumonia with my daughter, I was on antibiotics to clear it up and everything was fine. I was just put on amoxicillin for a dental infection. Both amoxicillin and the medication in your z-pack (I'm assuming that is what you are taking?) are both Pregnancy Category B and considered safe during pregnancy. I even specifically asked my Pharmacist and she assured me it is safe.
Much better to treat the infection before it gets out of hand and you have to use a stronger (and possibly less safe) medication to address it.