Yeast Infection ?

okay , so i've never had a yeast infection before so i'm kind of worried . at first it was like a itching feeling and the discharge was as everyone described it & there wasn't a smell so i was pretty certain it was a yeast infection .. but how long do they last ?

yesterday i got monistat 1 and like i said the discharge didn't have any odor , but when i inserted the ovule i smelt a slight smell .. so since there's a smell could that not be a yeast now ..? i honestly think the person i last had sexual intercourse with threw my ph balance off AGAIN but there wasn't a smell when it first began .. and there's reasonings why i can't go to the dr at this moment so i'm really just trying to figure out myself .. but i took the monistat last night and i feel better already i don't smell it right now either . but my question is could your PH balance be thrown off while having a yeast infection ? or should i be worried its something else ?