I Had A Pap Smear Done Last Week. My Physician

I had a Pap smear done last week. My physician called this morning and wants me to have an ultrasound done. Said i could have a polyp or an infection. My question is, I am a diabetic and I am on metformin. I was blaming my diarrhea on the med, but could it be because of the possible vaginal infection. I have had no symptoms.