If you have a legit have a sinus infection you may need an RX... Call your doc. Augmentin is a class B and safe for pregnancy. Sudafed is Class C, so see what your doc says about taking that. Some say it's totally cool, others may advise against. Mucinex is also safe... Just make sure it's just the guaifenesin and doesn't have all the other shit added in. Drink lots of fluids so your nasal passages stay hydrated.
I'm with @PinkLady2015 you need to talk to your dr each is okay and not okay with different medicines so it is best to talk with your own to get reccomendations. Try calling your nurse line
I love my NetiPot. ... I'm so stuffed up (I suffer from horrible allergies all year round and refuse to take any allergy meds while preggo) I've never been so happy to shove something up my nose daily. LoL
Re: What can you take?