weird smelling vag

Ever since I lost my virginity a month ago I know this is weird but I swear every time I open my legs I get a whiff of my vagina. 
It doesn't smell the way my vag normally smells. It isn't a good smell. But then when I go down to smell it or I check in the bathroom I smell nothing. 
Literally at random occasions as I open my legs I get a random funky scent. The same scent everytime. Then it goes away. Nobody smells it but me .. it's so weird. Someone explain !!
Yes we had protected sex no I do not have an std. we were both virgins. I do not have a yeast infection either because clearly I would've noticed that and gotten other symptoms . 
Yes I know Sex throws off my pH but what does that have to do with getting random funky whiffs ?? Especially if my vag doesn't have the same smell when I check it