Can a laser treatment cause the blood to coagulate under the skin?

I have rosacea on the side of my nose. I had a laser treatment to remove the veins. The first 2 times I did the laser treatment, I had no problems. The last time I did it, my skin burned and scabbed over, now under my skin looks black. It's been 10 days and no improvement on the discoloration. I have fair skin. What can I do? Could this be blood coagulation under my skin?