mild cramping and bleeding at 6 weeks

I am almost 6 weeks pregnant, and I've had mild cramping for the last 3-4 days, and today I started bleeding a bit, randomly throughout the day.. and my cramps intensified a decent amount from yesterday to today, I'm not bleeding or cramping nearly as much as I would be if this were a period, but too much to be spotting I would think.. the blood is about half bright red half brown.. I've been told that cramping is ok, and bleeding is ok, as long as you don't have both at the same time.. and I do! I have yet to see any tissue in the blood.. and I suppose I am just worried, but has anyone else had the same thing or something similar and found out they were miscarrying?