Why do I have a smell down there?!

I've had 2 partenrs my first one was 4 years ago an we both lost our virginity to each other, my partner I've been with now has been with 5 so we got tested together. I have no yeast infection, no std's I wash down there but for like 3 weeks I'll get no smell at all, an some days I'll go to have sex an it'll have the strongest smell I'm embarrassed. So I try an wash extra good an lotion non scent before I go with my partner. He never really says anything but he'll make fun of it here to there an we just laugh about it. I don't want to have this problem because I feel like none of his other girlfriends have had it? Does anyone else get a scent down there from here to there? Ah I feel lost tips please