I went to urgent care they gave me amoxicillin 875 mg for a sinus infection i only took four pills bike for 2 days and then i stop taking it and it's been a week since i took any can i start taking it again so being sick?

I suppose, but the delay could have triggered resistant germs now that will not respond. The prescribed duration is that needed to kill off all the germs, not most. Try it, but if you relapse maybe you'll finish the next round of a different drug.

The standard treatment is a longer course. By stopping the medication early, the infection probably was not treated. A full course is indicated, nasal saline helps to clear nasal secretions. A virtual consultation with Health tap is available. Consult with your physician. Watch for facial swelling, headache and fever.