Recurrent infections advice

About 2 weeks ago I developed BV and was given some medication by the doctor to treat it. My period is currently 9 days late (preg tests all negative) and yesterday ive developed thrush and I'm really sore down there.

I have the IUD.

In the past year I've had BV twice and thrush twice, and I was just wondering if anyone knows of any ways to prevent infections from developing and whether they could be making my period late?

Thanks!