It is normal to spot early on, but I would call my doctor just to be sure. Don't stress or think the worse. Call your doctor and they may have you go in for a quick check up.
Brown blood means old blood so you're fine. The pink spotting could be implantation which is common in early pregnancy. My implantation spotting was on and off for about three days, but it never went darker than brown or pink blood. If you get really intense cramping to the point where you can't stand it anymore or if the blood turns bright red or if it becomes enough to fill a pad, I would call your doctor or go to ER.
I'm almost 9 weeks but right when I turned 8 weeks I woke up and when I wiped I had pink spotting. Then as the day went on it was brown spotting and lasted maybe 3 days if that. Now I'm no longer spotting. Its all normal as long as it doesn't turn to heavy bleeding or severe cramping your fine!