You might try LOCALLY procured bee pollen, my midwife was telling me that some people get releif from their allergies from *local* bee pollen because the bees are rubbing up against all the stuff that makes you sneezy and it's in such minute amounts in the pollen that it works like a homeopathic remedy to reduce/releive allergy symptoms. Getting it from someone local is the key, though... the bees have to be in contact with the stuff that makes you react, any old pollen from any old bees won't give you the same effect.
I have'nt tried it, because my allergies are pretty mild. But it certainly could'nt hurt, and bee pollen has plenty of good stuff in it for you and baby anyway. I *do* take nettles though, but not for allergies. It's good stuff as well, I take it for its kidney supporting qualities.