I was on Metformin and it never regulated my cycles. After 2 failed ivf's, my endo increased my dose to 2000mg, up from 1500, and added 30mg of Actos. I had natural cycles for the first time in my life. It was that combination that did it after about 3 months.
I would suggest seeing an endocrinologist as they are the experts in that field. Met. alone helps some women and maybe your dose needs to be increased a little. I assume you meant 1000mg, not 100mg. I really never thought that just adding Actos would work, but it did. I reread your post, so you are ovulating on met., right?
I like FF for charting. You've come to the right place for help. Charting is such a valuable tool even though it's easy to obsess a little too much.

You'll learn a lot about your body through charting. And I ditto the TCOYF book. It's a must read! I hope you can find your copy soon!
I would also suggest that your dh get tested. You never know what can change. We thought our issues were all about me, but a thorough s/a confirmed we had male factor issues as well. All the post coital tests and even a quick s/a never caught the male factor issues.