Vaginal odor

I gave birth to my son 9 weeks ago. I was bleeding for 3 weeks, stopped for a week then started back up for about 10 days then it's stopped completely (by 6weeks). I had sex with my fiancé for the first time since giving birth a little over a week ago & since then my vagina has had this awful odor!! Its not a fishy smell, It's more like a musty, dirty vagina smell.  Even after I take a shower. Literally I'll shower, dry off, get dressed and 20 mins later it will start to smell again. My SO says he can't smell it (i won't let him down there lol) but I can smell it when I'm sitting down or going to the bathroom. Can anyone relate??? Help me :(