yellow vaginal discharge

[helpmeknow]

hi. so every since  i started having sex i have noticed all these problems. i first had sex feb 24th/07 and the last time aug 7th/07 in total iv had sex 4 times. i dont know if thats relevant information. so my question(s) the day after i first had sex i was in pain and was bleeding lasted for a day then i got itchy white discharge witch went a way once i got my period, i keep getting 'yeast infections' if that’s what it really is a week or tow weeks before my period but gos a way once my period starts. i recently used monistat  3 day care and that helped a lot with redness and itching.

i also started noticing a yellow/greenish discharge in august a few weeks after i had sex. i went to the doctors and she never looked at me i just described what was going on and she gave me an medicine called Metronidazole i took it for 7 days and it did end up going away. but now im noticing it again. the discharge looks white till you see it on toilet paper then you can tell its yellow. sometimes it more yellow then other times. any idea whats going on?  i do have a doctors appointment on wednesday.

I really hope its nothing serous. *crosses fingers*

thank you.