Chest infection?

I have had a chest infection with nearly 2weeks now.i finsihed the amoxicillin 2 days ago (though i skipped taking it for a day)i feel i still have it( probably as i skipped)i dont feel feverish but i still have phlegm problems(no cough really)should i go back for a different type of antibiotic or will it go away on its own?thanks