Positive on one brand, negative on another?

[jinglybell]

I've been ttc for 11 months. Testing each month with one brand. Never had even a hint of a line.

My period is now 2 days late. Ive tested the last 4 days with the same brand ive been using the whole time and got a faint positive each time.

Today i checked with fmu and an early response and nothing. Tried again with 2mu and the same brand ive been using since i started ttc, another faint positive.

The brand I've been using is not as sensitive as the first response, yet is giving me positives?

I've googled and found the hook effect - could this be why the less sensitive ones are working and not the first response?

My last period was a little off - not as heavy, no pain. I have adenomyosis so periods are usually agony.

Could i be farther along than i think which is why im getting faint positives on the less sensitive brand and nothing on the first response?

Any thoughts would be very much appreciated!

Are the first response tests you are using the early response or the rapid result? The rapid result tests are less sensitive - I had positive tests on wondfo cheap strips but negative on the first response rapid results when I first tested, it took a few more days for the frrr test to give me a clear positive.

I used the early response, to use from 6 days before your period is due