I totally understand. I think it's perfectly normal to have pregnancy symptoms come and go--and of course it must be even scarier with a m/c in your past. I worried too, TONS, throughout my first trimester. I'd constantly feel my boobs--were they still sore? Did I have m/s (not that I really wanted it, but hey, it meant the babe was growing)? I'm a worrier by nature, and the first tri was super hard.
But I made it through (my son is due in six weeks now) and the chances are *very* good that you will too. I agree with others, try to take it one day at a time, and know that a past m/c is really no indication of anything, OK?
Oh...and I must have taken eight pregnancy tests in the first couple of weeks. (Told ya I'm a worrier...) Hang in there--I'll be thinking about you!