UTI or BV questions…

I’ve been w my partner for almost 2 years and never had a UTI or BV. I’m kinda weird about my personal hygiene, so I don’t bathe w soaps, I don’t use anything to clean my private parts except soap and water, and never scented soap on those areas, and never inside. My partner has been acting really weird lately. All the sudden wanting to try specific things in sex, which I never thought twice about till I noticed he’s also become secretive and hiding his phone. After our last little go around, I woke up that morning and could tell I was developing a UTI. Just the uncomfortableness, the urge to pee but nothing much came out. Idk. A friend who I was complaining to ab the need to go see the doctor this week told me a sudden change in something like that could be another hint that my partner is messing around with another female. Wondering if that’s true? We just had a baby 8 weeks ago so I’m rlly hoping it’s not😅