What Causes Stomach Cramping After Starting Treatment For Vaginal Yeast Infection?

I started using a vaginal yeast infection treatment YESTERDAY {not over the counter} and immediately I start having cramping pains in my lower stomach, this morning I was still having pains but I start bleeding some. It doesn't seem like a period, does it look like one. Me snd my husband recently bought a pregnancy test. We think I may be pregnant, I haven't took the 2nd test yet, I was going to wait after my missed period. Am I miscarrying?