Is mycoplasma pneumonia contagious during the incubation period?

Yes: Like any infection it can be contagious during incubation period.

Yes but........: It is difficult to say when the incubation period started. Mycoplasma is commonly diagnosed with a blood test. The problem with the blood test called igm is that the test has too many false positive (i.e. Positive test when the disease is not present or when it has resolved), a new test called pcr is really good but most clinics do not offer it.