Diagnosed at 27 after missed period?

I am new to the board with so many questions. I started my period around 11/12. I have always had regular periods, usually down to the day. My husband and I tried for 18 months to get pregnant and finally conceived our son right before starting fertility treatments. We conceived in February 2015, healthy pregnancy and delivery in October 2015. At the time of conception, blood work showed slight insulin resistance so I began metformin. PCOS was never mentioned at that time. After delivering my son, my periods got back on track around 3 months PP. I have been regular since then until this month. My last period was January 24. I scheduled an appointment with my doctor when I was 3 weeks pregnant with BFNs. They did bloodwork Friday and called Monday; bloodwork shows evidence of PCOS. I go tomorrow for a fasting glucose test. 

I am terrified because we were getting ready to try for #2. Is it normal for PCOS to develop in late 20s , even though my periods have always been regular???