Equate tests reliable?

Ok so this cycle I tried using OPK's to pinpoint my 'O' day and I'm pretty sure we hit it because we BD'd all through my fertile period. Anyways, yesterday morning I was 11DPO on a regular 27 day cycle and took an Kroger Equate h.p.t. and the + showed up right away! But after a little while the whole + faded completely and now you can barely see the lines in the result window... So I took another one this morning and it was like a + but shadowed kind of? Then it looks like BFN. What the heck!?! What do I do? My LMP is 10/08/10. So someone do the math. AF is supposed to be due tomorrow but after yesterday's "positive" I feel like she's going to be a no-show this month.. So should I get a different brand or get a digi? The Equate was pink-dye if that helps any. Thanks!! :)