vaginal odor after prolonged sex

I've noticed that the only time I have a problem with fishy vaginal odor is for a few days after I've had PROLONGED sex. Is it possible to get an infection just from having too much sex at once?? It's always happened with any partner I've had and seems to disappear within a few days. (This does not happen with regular sex, only with "marathon" sessions, if you know what I mean). It is embarrassing to have a few great sessions in one day and then have to make excuses for a week as to why I'm "out of commission" because of the funky smell. Why does this happen?

I have the exact same problem. I've been searching on the internet for some kind of answer but I've come up with nothing. Everything I find about odor says "check for std". But, like you said, it only happens once and a great while and for me..only after 'marathon' sex within a few days after my period.

I think I read somewhere, the first time this happened to me, that it has something to do with your system cleaning itself out. But I want to get a back up opinion. I'm going to just ask my gyno at my next appt. I'll post her answer asap.