Scared to Death!

Crystal • Child loss survivors currently trying Rx w/intercourse following removal of uterine septum, Endo, and fibroids.
I'm 3 1/2 weeks and have a history of multiple miscarriages. I've had light spotting off and on a couple of days. Today I had redish-brown spotting, like dried or old blood at my first morning pee but nothing else since. My breasts also aren't hurting as badly. I feel like my pregnancy symptoms are going away a little at a time. The spotting scares the crap out of me and I am FREAKING OUT. 
I can barely keep it together and I have to go to work. I'm calling my OB when they open in an hour or so but I know if I am miscarrying there is nothing I can do to stop it. 
I read somewhere that brown spotting is common around the time you should have had your period. I was supposed to start in a couple days. I could really use some encouragement.