First period on metformin

Hi! Just diagnosed with pcos after not having my period for 3-4 months. I was given metformin 500 1x per day. It’s been about 30 days and I started (what I thought was my period) began with brown spotting then turned to bright red spotting, got heavier and then bam back to brown. Then one day stopped and today it’s back bright red again. This is my period right? I’m not even sure how to count this or if this is ok. I guess just my body getting used to it?? Any comforting experience?