Just diagnosed with PCOS but I'm afraid it's a wrong diagnosis

Hello everyone! I'm hoping someone on here might have or have had a similar situation to mine... for the last 6 weeks I have been having abnormal uterine bleeding, flank pain and constipation. My ultrasound showed fluid in the uterus, a small cyst with debris on my left ovary and a thickened lining (28.5mms). My blood work all looked great except it showed low progesterone and possible prediabetes, now my doc is saying it's PCOS. This makes no sense to me! I don't have any other symptoms (hair growth, hair thinning, dark spots, etc...) and my blood pressure has always ran low. (Its my understanding the PCOS raises your bP). Any thoughts or ideas?