Is it safe to take amedicine for sinus like afrin (oxymetazoline) in the 1st trimesters of pregnancy?

FDA Category C. This substance is rated category c for pregnant women. Which means it is not advised unless the benefit outweighs the risk. There have been very few reported problems, but no real studies have been done to establish safety. As a fellow sinus sufferer....I would not use it. I would do steam inhalations with menthol and consider seeing the doctor if symptoms last longer than 10 days. Good luck.