The kind of rash you describe sounds viral. Chickenpox is indeed a strong possibility. The classic description of chickenpox lesion is a "dewdrop on a rose petal," which certainly fits your description of "red bumps with a clear fluid." The time interval between exposure to shingles (zoster, which sheds the chickenpox virus) also fits quite well. An experienced clinician should be able to diagnose this quickly, without a blood test, which would not be helpful at this point anyway. As much as I can say from a distance, your doctor sounds right on.
Best.
Dr. Rockoff