After sex smell? Help?

So after me and my boyfriend have sex I notice my vagina smells like cheese🤢🧀.

He always has a bath before we have sex and I always shower before so we're both clean.

If I wash it goes after, it's not constant.

It only smells like that after sex even if he doesn't cum in me.

Does anyone know what this could be?

•I have the implant

•We both don't have any STI's