brown spots on hand

I noticed 2 small dark brown spots on my right hand. First one appeared about a week ago on the outer part of my index finger. At first I thought it was a splinter but apparently not. Then the other appeared on the front of my hand toward my wrist , sort of under the thumb area. The 2nd one started out red then turned brown. They are flat not raised or bumpy. The one on my finger is almost a very thin triangular shape -it's quite small. The one on my hand is a very small circle (not perfectly round). There are no symptoms at all - no pain, itching etc.  Should I be concerned about these?
esther