Ok, so I tested using a Crystal Clear HPT this morning with FMU, even though I'd been up and down to the loo for half the night, and at the 3 min mark a very very very faint bluey-grey line came up. There is no colour when held up to the light, but sitting on any surface that faint bluey-grey line is still there, approx 1mm-2mm wide, with the white line (that Crystal Clear seems to have on it before testing) running down the middle of it.
I also tested last night with a BFN, and comparing last night's one to this morning's one there is a definate difference.

I can't get a clear photo of it though, or I would put it up here.

So anyway, I'm just wondering if anyone else has had this happen and been pregnant? And if you could share pics that would be even better so that I can compare (and prove to DH when he gets home that I'm not just imagining things!).