Hi there, I am in the EXACT same predicament as you. I am currently on day 12 with no period. I took a Home Pregnancy Test ( Clear Blue Digital ), and it came back negative.
I have been really, really tired, & bloated. Though I'm not sure if it's related to actually being pregnant ( though I'm usually never either of those things typically).
I worry a bit as I had a miscarriage in April, and fear something may not be right again...
I am going to take another test tomorrow ( Day 13 WOP ). If that comes back negative I am planning on going in to get a blood test next week. Just to make sure there isn't something else going on, and alleviate the possibility that I may be pregnant ( which would be wonderful, but I'm not counting on it at this point ).