pH thrown off

I had sex with this guy one time about 1 year ago. Ever since having sex with him, my ph has been thrown off & I don’t know what to do about it. I’ve gotten tested & I don’t have any std / sti, yet I still have a strong smell of BO down there. Again, I never experienced this prior to having sex with him. I’m 30. Does anyone know how to solve this??? I’m in desperate need as it is just making me very self conscious.