White blood cells?? please help!!!!!!!!!!?

Ok so i might be freaking out for nothing because i do that to myself sometimes lol but today i went to see my doc bcuz i had the mirena birth control put in about 3 months ago and lately i was noticing weird discharge that smelled odd which never ever happened to me and thought it was an infection. Anyways i saw the doc and he swiped my discharge with a q-tip plus did that thing where they put like 4 fingers inside you and press to see if there is any sharp pain and i was good on that department but when he did the swap test and looked at it under the microscope he said he saw a few white blood cells which meant i have a minor bacterial infection aka minor vaginitis. It freaked me out a little because it made me think of std's plus i never had this before in my life until now after having a baby!! i ony had 1 man my whole life but still. Anyone else had this problem?? the doc wasnt concerned he said this is a common problem and gave me antibiotics but sent the sample to the lab to make sure nothing is possitive... i mean possitive from what?? please help ease my mind a lil so i can go to sleep! lol