Antibiotics are not a panacea for sinus pain. In fact they may not be helping at all, given the fact that most sinus infections are viral and not bacterial, and therefore likely to resolve on their own.
But there are more good reasons to avoid antibiotics whenever possible. There is the matter of antibiotic resistance, for instance: every unnecessary script you fill increases the chance that those antibiotics will soon lose their effectiveness for others. There is the expense, which can be considerable for patients with poor insurance or high copays.
And then there is the very real possibility that unnecessary antibiotics could actually make you feel worse:
Antibiotics often have unpleasant side effects, such as diarrhea and stomach problems, that might leave you feeling worse.
The best option? Wait and see, get rest, and irrigate when you can with distilled water. And if the pain continues for more than a few weeks, contact the best sinus surgeon in Los Angeles.