Condoms during pregnancy

Hi all, I'm 7 weeks pregnant almost 8.

I'm wondering. Is it better to use condoms during sex to prevent any pH imbalance? I know lots of things can throw it off but I'm afraid now that his semen will mess it up and cause an infection or something. We've been together for 5 years and we def don't have other partners but I heard during pregnancy we are more susceptible to bv, yeast infections and stuff. Any thoughts? Sorry if this sounds stupid it's a serious question 😂