Oh Dear.. I also had sore throat before chinese new year.. At first, I tried to gurgle salt water as I dont't want to take any medicines. You can also take lozenges. But these kind of remedies are only to make better for minor sorethroat.
But if it is the bacteria infections, gurgle with salt water also could not help. You will even get fever later.
That was the case for me. After sore throat, I've got fever and coughs. So I have to go to nearby clinic and doctor gave some antibiotics which is safe for pregnancy. The best is to go to clinic and get some advice from doctor if you have sore thorat for a few days. Tell them that you are pregnant and they can give you the relevant medicines.