Yeast infection ?

I think my partner caused me to get a yeast infection, I don’t think it’s a STI. Just itchy here and there. I’m gonna treat it with Canesten and I have a STI test appointment Wednesday to test cause he’s a new partner.

What I’m concerned about is if this is a yeast infection (I’m pretty sure it is) won’t he keep giving them to me every time he gives me oral? Like how do I avoid this?