Have you tried using a saline nasal spray before you go to bed (eg. fess or narium) to thin out the mucus? (which is probably why you are snoring more than usual - all that pregnancy congestion!!).

Also, you could try nasal strips - they stick to each side of your nose and pull your nostrils open a little, to help you breath better through your nose. They are advertised as stopping snoring. The product is called "Breathe Right Nasal Strips". I haven't used them, just seen them advertised & sold them (I used to work in pharmacy).