No period after starting Glumetza ( Metformin ER)

Hey ladies, my periods was irregular ( 35 -45 days) and I was recently diagnosed with PCOS. I've been taking Glumetza 1000mg for the last 45 days and is yet to have a period after starting them. LMP was 54 days ago. Has anyone experienced this after starting Glumetza/metformin? No pregnancy symptoms and got several BFNs.