Could Delayed Periods Along With Spotting And Sore Breasts Be Due To PCOs?

Hi , I've been on metformin for 4 months cuz of PCOS and since I started taking it my periods have been normal for me..and now I missed my period this month fallowed by light spotting, sore breasts ,armpits, nausea,peeing a lot and I took a home pregnancy test and came back negative...just wondering if I could be pregnant or if it's just my PCOS