Do hpts become less sensitive over time?

😶‍

So I tested a couple of times in the past few days and had bad dye runs, I checked my cheapies for the expiry date and lo and behold they're almost a year out of date. Needless to say, I binned them all.

I was reading up on expiry dates and shelf life this morning and I read something on the What To Expect website that got me thinking...

Do hpts become less sensitive to hCG over time? Even before the actual expiry date?

Maybe it's obvious? As someone who has been ttc over 3 years I have a lot of cheapies lying around, some haven't expired but it's still around 2 years since I bought them. Do you think they would still be as sensitive as a test I were to buy today?

I know it really doesn't matter in general but it's got me thinking I probably won't buy in bulk anymore 🤔