I am 9 1/2 weeks along and just came down with a terrible cold a few days ago. I never use antihistamines or decongestants anyway, but I do use Zicam, which has been very effective in shortening the duration of my colds. I can't imagine that it could be bad for the fetus, but want to find out if anyone knows. The problem with asking my doctor/midwife is that they don't usually know anything about homeopathic remedies, so they usually say not to take it.
I don't know what Zicam is but I wouldn't. Even herbal remedies can cause problems sometimes. I feel for you as I just got over the worst cold of my life (in about month four of my pregnancy) - my head and throat were full of the most disgusting junk, I was constantly choking on it, sneezing, blowing my nose all day and night, couldn't sleep 'cause I couldn't breathe while laying down but if I used a bunch of pillows to keep my head high enough to breathe then I would wake up from the sore neck.... It sucked completely!
I would suggest drinking lots of water and OJ and hot decaf tea. Hot chicken soup. Hot showers (the steam is helpful). Lots of rest. Take your vitamins. It will pass. Hopefully quickly!
I personally wouldn't take anything during my first trimester. Drink lots of hot liquids, I find hot lemon water with some sweetner, honey, sugar, works really well, sit in the shower, get lots of steam and rest.