I have the worst immune system, and every time I get a cold this pregnancy I start drinking green tea with fresh squeezed lemon 3x day, I swear within a couple days it's whiped out..... The tea has strong antibacterial/antiviral properties and lemon helps boost the immune system and also a natural antibaxterial.....
You can also take a lot of allergie meds to help with runny/stuffy nose.... I took a lot of Zyrtec the first 4 months of pregnancy, my first pregnancy I took Benadryl the entire time..... Suedophed is also safe, anything tylonal except tylonal with a decongestant ..... My dr gave me a huge list but I don't have it around :/