Test line darker than control line?

I've been taking tests periodically over the last 2 weeks because I'm very nervous to MC again. This is my 3rd pregnancy. The first ended in termination in the begginning of my third trimester due to incompatibility with life outside the uterus and my second ended in a MC and D&C last March. The bottom test which I took today is making me nervous. The test line showed up immediately very dark before the urine had even made it all the way across the window. The control line took almost 3 minutes to show up. Does this mean anything or am I just worrying too much?