For the past 3 months I've just gone off of the <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> to see when I'm most fertile but 3 months and no bfp. I figure I better start using opk's but not sure what brand to use?? Any suggestions? Digital vs lines?? I'm going to try preseed next cycle along with the kits so hopefully I'll get a bfp!