I got a really nasty cold too when I was pregnant. Relied on home remedies.
1- Gargling with hot salt water ? 3-5x a day (great for removing the phlegm)
2- Steam inhalations ? Boil some water, add a spoon of Vicks. Get a towel and cover your head, making a tent, and inhale the steam. Helps clear air passages and loosen the phlegm.
3- Drink lots of hot liquids and vitamin C.
And lots of REST! Hope you feel better soon.
:bighug