embarrassed and nervous

I'm going to be totally blunt so beware. My bf usually just rubs my clit to make me cum because fingering usually feels weird for me, anyways he fingered me for a few minutes, his fingers were soaked and I went to kiss that hand and it smelt bad. Like fish bad :(  he wanted to eat me out, so instead of popping his head off his shoulders by squeezing I just let him....he obviously drank water after he was done but he said it didn't taste or smell like anything. Do you think he's lying just to be nice? We live together and he doesn't seem like anything is different. The thing is me and my bf have a past and a few years ago, one of us gave the either an std. I've been completely faithful to him since we've been together. So my question I guess is could this be an imbalance in my Ph to make it smell bad or does it seem like something worse like an std again? :,(