Opk help please

[lilmisscaviar]

I've been using the same brand of opks (Wondfo) for the past four out of my five pregnancies. After being unable to become pregnant for three cycles now despite having had positives on the Wondfos at CD 13/14 the past couple cycles. I have decided that if I don't get pregnant by Christmas, I may try using a different brand. I bought a couple $ store tests as an experiment just to see if they were different from my Wondfos and they were. The line was much, much darker. Does each brand of test have a different level of sensitivity? Is it possible that I may be missing my surge using the Wondfos?

 

[RoseArcana]

When I used OPKs when TTC my DD, I never got a positive (I only ov'd twice in 7 months but still). I did some research this time and ordered a higher sensitivity batch of tests. One step from amazon - you can choose sensivity. Had my first positive last month. How positive have the wondfos been? I did read that LH surges get shorter the older you get x