Brown spotting in first trimester? Concerned

I am about 8 weeks pregnant and have been having some off and on brown spotting. It's usually when I wipe and it's not all the time when I wipe. It's been going on a little over a week now. Today I wore a light pad to see if it would be on it and there were a few spots as seen in picture. Should I be worried about this? This is my second pregnancy. I don't really have pain. Maybe a cramp once and a while.

Had ultrasound at 6 weeks with strong heartbeat.