Allergic rhinitis: The patient is taking Flonase (fluticasone), a common medication for allergic rhinitis, which suggests that she has a history of allergies. The symptoms she is experiencing are consistent with allergic rhinitis, which can worsen during pregnancy due to hormonal changes.

Pregnancy rhinitis: This condition is characterized by nasal congestion and rhinorrhea during pregnancy, often without a clear allergic cause. It is a common condition in pregnant women and could be exacerbated by or mistaken for allergic rhinitis.
Viral upper respiratory infection: Given the patient's symptoms of allergy-type symptoms, a viral upper respiratory infection (such as a cold) could be a likely diagnosis, especially if the symptoms are acute in onset.

Preeclampsia: Although less likely to present with allergy-type symptoms, preeclampsia is a condition that can cause a variety of symptoms, including those that might be mistaken for allergies, such as visual disturbances or severe headaches. It is crucial to rule out preeclampsia due to its potential severity and impact on both mother and fetus.
Anaphylaxis: A severe, life-threatening allergic reaction that requires immediate medical attention. While the patient's current symptoms may not suggest anaphylaxis, any sign of worsening or severe allergic reaction should prompt consideration of this diagnosis.

Churg-Strauss syndrome: A rare autoimmune condition characterized by asthma, high levels of eosinophils, and vasculitis. It could potentially cause symptoms that might be confused with allergic reactions, but it is much less common.
Angioedema: A rare condition characterized by the rapid swelling of the skin and mucous membranes, which can be life-threatening if it involves the airways. It could be considered if the patient's symptoms include significant swelling, especially of the face, lips, tongue, or throat.