Lean pcos on metformin and ovulation yest positive on day 24

morning,

myself and my husband been trying for 2 years, got diagnosed with lean poly cystic ovaries at the start of September and got put in metformin twice a day so 1000mg. Had my first period on 28th September after taking tablet for 2 weeks and have been doing ovulation tests daily since.

around day 12-14 line started to appear but never got as dark as the control line. Then disappeared, then day 17 got another line that appeared but not as dark, then gradually from 19th Oct high was day 22 line has been getting darker and Yesterday on day 24 after my period was very clearly darker, first time in a year I’ve ever seen it, obviously dtd and again this morning did ovulation yest today and line is still there but not as dark as yesterday. 

previpusly my periods were average around 35 days but ranged from 30-40 days. weve been trying so long I’m concerned this positive ovulation is a freak reading as told if my cycle is over 35 days unlikely to ovulate at all? Anyone experienced the same thing I feel so down hearted about it all! 

thanks in advance for anyone’s time