PH balance off

I don’t think I’ve had this problem before but I’m sexually active, but my boyfriend never finishes inside me.

Sorry for the TBI

So last week I was having sex with my boyfriend and I was on top then I went down on him and and it tasted sour? But there was no smell.

I ate a bunch of yogurt and did a few apple sider vinegar baths but yesterday we did the same thing and that sour taste was still there.

Is there anything else I could be doing? I don’t have any pain and there’s no bad smell or color/ texture change in my discharge just the sour taste.