15 days late negative tests

So I’ve gone to the drs to see why I’m not getting pregnant. Dr said high testosterone which is known for pcos but I had ultrasounds done and she saw no cysts. Also A1c comes out fine. My af comes every 32/34 days. My bf just moved in and I thought I was pregnant even if I had no symptoms. We don’t use any kind of protection. I was prescribed metformin but I stopped taking it because 9 months ago it made me bleed for 2 months straight. Any of you know what could cause it? I always get my period even if I don’t ovulate which is weird. But I’m 15 days late and the tests come out negative.