Antibiotic use after surgical mole excision

I was on azithromycin for sinus infection and had to have a surgical mole excision (the ellipse was about an inch, maybe a little over, 8 stitches) on my back. I was prescribed Amox-Clav and told to take it the day after I finished the azithromycin (I finished the azithromycin 3 days after the excision). Do I really need it? The stitches look fine, and I'm starting a new job so I'm worried about the amoxicillin upsetting my stomach. The last time I took it 2 years ago I threw up for a whole day.