I just finished up some medicine from a sinus infection and ear infection. now i have a vagina odor. the smell came out of no where. any idea?

Bacterial vaginosis?: The main cause of strong vaginal odor is bacterial vaginosis, overgrowth of mostly normal vaginal bacteria. Some antibiotics can trigger BV by suppressing protective bacteria. Antibiotics also can trigger vaginal yeast infections, but usually no odor with yeast. See your doctor; if BV confirmed, you'll need a prescription antibiotic. (An antibiotic to treat an antibiotic problem? Yes, probably.)