first of all you need to know that once done strep test
has specificity of 95% - 98% and sensitivity of 95% and once negative it should be followed up with a culture (24 hrs to 48 hrs) to diagnose infective organism. You have been given antibiotics and steroids
that might have a synergistic effect on tonsillar infection and your sublingual problem. If the tonsillitis
is recovering then probably the antibiotic is prtially covering the spectrum. Take a medhelp and get a broad spectrum antibiotic till you come back and get a throat culture
done. Remember to stop antibiotic atleast five days before you give a throat swab sample since the effect of antiobiotic may interfere with the culture reports.