Waited past 5 minutes....

Laura
We have been trying to get pregnant (and stay pregnant) for over a year and a half. I had two back to back miscarriages and have had trouble getting pregnant ever since. I'm on my 3rd round of clomid, took a HPT this morning...it was negative after 5 minutes. A few hours later I saw it sitting in the trash can and I could tell there was a faint line.
I shouldn't trust this should I?