Missed Metformin + OPK and AF

So I have PCOS and have been off BC for 2 years.  I've been on Metformin for a couple months now to regulate my periods and it works well.  I always use Clearblue Digital Advanced and always have peak fertility days but I've never high.  This month has been really strange.  I had 3 days of high fertility and then today I had a peak I also forgot to take my Metformin the last two days and it seems like I may have started my period tonight. I am so confused!  Any one have any insight?? Is my positive opk reliable can I still conceive this this ovulation? I have an appointment with my OB Friday she was going to check my progesterone levels one week after +opk so I will talk to her about it then but in the mean time I could use some support and insight! Thanks!!