Pregnancy and hypertension?

I was distraught to learn at 5 months pregnant that I was suffering from hypertension--me, the healthy one! My husband lives off of cheeseburgers and Pepsi, and he has perfect blood pressure. No fair! Anyways, rather than fatten my HMO up with weekly co-pays, I have been getting my blood pressure checked with these guys. I have also been walking more and eating more leafy greens, and I'm happy to report a significant improvement, but I still need to do better. Any suggestions for NATURAL ways to improve my blood pressure?