A few bits of stitches left in my scar

I found about 3 little places where it feels like there are bits of stitch left in my incision.

The feel hard and wiry and are black.

Can't see very well other than that.

I have red hair so it's not my hair.

I also found a small piece of one in my hair this morning.

I tried to pull gently on it with tweezers and it will not budge.

My next appt is Feb 20th

Is it okay to wait til then to let the Dr take them out?

I am into my 4th week post op.