What Causes Vagina Odor?

i have a foul odor in my vigina, i am afraid that it might be an infection, what should i do to remove that kind of odor? what kind of antibiotic should i take. because i remember the last time i had this i just drink a antibiotic but i forgot what it is. i am afraid to go to doctors. my obgyne is out of the country, and i think i cant wait for her this smell irritates me and makes me embarrassed with my boyfriend. can you help me please thank you...