tryingforone

I am 35 and have been ttc for 3 years, I have taken several clomid and shots cycles. I was diagnosed with PCOS April 23rd or so, felt like I was getting the first real answers, I have always had irregular periods but they are usually around 34 days apart or so, sometimes a little longer and sometimes a little shorter. My last period began April 19th and I started Metformin on April 24th and I am now taking 1000mg a day. I expected a period around May 23rd but now almost a month late and Im beginning to worry. Is it possible metformin can make my period run later than normal, also I have been having cramping like my period is coming for over 3 weeks, they come and go throughout the day, some worse than others, they are more mild now then they were 3 weeks ago but still daily, painful and depressing. I have had all the normal side effects with metformin, stomache problems ext, but the cramps I am experiencing started around when my period should have came. So is it normal for a period to come later than usual, and is the period cramps for this long normal?
Thank you!