UTI / STD in Marriage

So have read on this app quite a few women finding out their husbands cheating through an STD.

This got me thinking about my own marriage. I blindly trust my man but we don't live together. Twice in our marriage, I have had a UTI after having sex with him. When I feel it, I tell him and he gets me medicine immediately. No big deal. He is a doctor. Once he told me it is normal for women to get UTI. That it happens. And made it sound like it is my fault. I also told him but why do I only get it when am with you? He said sth like the bacteria that I already have can just be transfered inside through sex. Anyway I let that pass.

But now, as my trust in him has faded more and more, it hit me that I would never know if I got an STD from him or not if I continue consulting with him first. He doesn't check me or anything, he just brings me antibiotics and I take them and am fine. Like if he had it before and treats himself, then I get it and he treats me. Now am starting to think next time this happens, I shouldn't tell him, I should go to another doctor and first get checked. Is this toxic for me to do? Is it bad to not trust him? Or should I be wise and take this measure from now on so am not blind sighted. Truth be told I think both times it was a UTI. I havent seen him flirt around so I should have no reason for mistrust but also I don't live with him long enough to see that.