Yeast Infection

Has anyone got a yeast infection due to pregnancy before a missed period?? I’ve never got yeast infections unless I was on the pill... and this one is horrible and I am not on the pill. I’m just now in my fertility window so I feel like it’s too early for it to be a pregnancy symptom but I also had horrible cramps yesterday that could have been ovulation? I don’t know I’m just trying to figure out how to explain this yeast infection or determine if it really is one. I did a Monistat last night and it’s way worse this morning. Please help, when I do get yeast infections they are HORRIBLE. Last doctor I saw when I had one said it was the worst he’s ever seen and gave me 3 different types of treatment. I really don’t want to have to go through that again and if I can prevent it by knowing what caused it I will do anything!