OPK help please

Diagnosed with PCOS in 2013, been on Metformin since Jan and have had regular cycles since Feb/March. I've been using OPKs but never get that positive second line 😞 I've only been using them this year so idk how dark of a line to consider a positive LH surge....any opinions or advice?? I know these are still kinda light but like I said I've never had any kind of line before and am still pretty new to OPKs. (That's why I took two 😂🙈) DH and I are going on 3yrs married and TTC for our first. Thanks in advance!!