I feel for you! I had BAD allergies throughout my pregnancy - so bad my OB, the pediatrician, and my allergist had teleconferences about me (they included me). It was not just miserable, but dangerous.
But towards the end of pregnancy, they do relax some about what we can take. I could take Benadryl. I agree with you about any medications, and I hope any curious readers will consult a doctor before taking even OTC allergy medications or supplements during pregnancy.
Here are things to help:
* Wear a pollen mask outside!
* Use electrostatic filters inside (this goes on your central airconditioner.
* Have someone else do the vacuuming.
* There is now more than a Neti pot - there are nasal sinus wash products (A friend swears by the one he buys at Rite Aid).
* Make sure your bedroom, at least, is as hypoallergenic as possible - especially your pillow and mattress(allergies are cumulative), even if that means buying a new pillow and using the special mattress protectors (they completely encase your mattress).
* If you have needed antibiotics during the pregnancy, look into using probiotics - not just for you but for your infant. Klaire labs does have a type safe for infants (http://itsnotmental.blogspot.com/2011/03/gut-brain-and-ba...)
* Some supplements to ask your doctor about that may help are Quercetin and Butterbur. Oh, and Boswellia.
And congratulations on the wonderful upcoming event!