TTC with Metformin

My husband (33years old) and I (27 years old) have been TTC for 7 months now so I made an appointment with my OBGYN for a general physical and to let her know we were TTC. I have a regular 29 cycle and used OPKs which say I ovulate between CD 16-18. She wanted to check my progesterone level on day 21 which last month was only 3 DPO and my results were 2.8 which were low. She thinks I missed ovulation but doesn't think I have PCOS because I have no other signs or symptoms plus she ran every test known to man kind two years ago and said everything was perfect. She started me on metformin 500mg for the first week and now I'm taking it twice a day which is 1000mg a day now. I am on the keto doet and lost 25lbs since January 5, 2019. I exercise 8 hours a week plus sleep 7-9 hours a night. I have been doing the OPKs since CD 7 in case metformin made me ovulate early but I finally just got my postive opk CD 16 plus I'm tracking my bbt this month. Has anyone had any success taking metformin who doesn't have PCOS and a regular period?