Yeast infection/pregnant/difficulties!!!

I’m almost 31 weeks pregnant. I developed a yeast infection and my doctor told me to use the monistat 7 day cream. Idk why, but it’s been HELL trying to insert that tube up into my vagina. It’s like my vagina literally closed and won’t allow anything inside. It hurts so bad to put that tiny applicator up inside me. Almost like losing my virginity every single time. Is this normal? I’ve never experienced this and was just hoping it’s a “pregnancy” thing. Only 3 more days left of this dang medicine!!