I know the feeling! This is the first 'sticky bean' I've ever had, so I've always got a nagging feeling that something will go wrong. My previous losses have been between 4 & 5 weeks, though, and I'll be 8w tomorrow, so that's promising. I also got my first round of bloods back and everything was great, according to the doctor. That really put my mind at ease, hearing that.
In general, I keep reminding myself that the bloating, breast tenderness, etc. I'm feeling (even if it's not constant) are good signs, and I keep checking every time I use the toilet to make sure I haven't started spotting. I'm seriously wondering if I'll be doing that the whole pregnancy, or if I'll get used to the idea that this one's sticking some time soon.