I have no idea if this would help, but there is an old-wives-tale that say the you can sniff seawater/very saltwater for blocked sinuses
After being fed-up with sinuse-meds that did not work, I did just that (I was not pg) and yes it clears the sinuses, but it burns like high hell, so be prepeard.
I sounds medicaly incorrect and I am sure that it's frowned apon by drs, but hey, it worked for me