I've Been Sick With Allergies For About A Month And

I've been sick with allergies for about a month and have been taking over the counter medicine. I had sex over the weekend and a couple of days later my vagina felt irritated. It was red and itchy with some discharge. I've had yeast infections before so I purchased the monistat 3 day applicator. When I insert the cream, I get a mild burning sensation, which I've never experienced before. I felt a little better after the first night of usage but not how I have in the past. Could this be another type of infection? Or should I continue with the monistat?