Sinus infections are contagious and can be spread from person to person easily so you could give a sinus infection to your coworkers especially if you happen to work close together as in an office.
If you do go to work with a sinus infection you may not be as productive anyway so it would be best to stay home until you recover from the sinus infection.
If you have a fever with the sinus infection you should stay home because when you have a fever with the sinus infection you're almost always still contagious.
Do yourself and your coworkers a favor and take a few days off from work until you're feeling better from the sinus infection.
Sometimes you can be contagious for a few days even before you got the sinus infection and then when you get the sinus infection you can be contagious for a few more days afterwards to as long as a week.