I removed the stitches twice, but is it normal for some stitches to remain?

Hey guys, I don't know much since it's my first plastic surgery, but
 after the surgery, I had the first stitches removed (only a few) and the second (all of them), and after the scab fell off a bit, I looked in the mirror and was dressing myself when I
 found the stitches.
 It was hard to see because of the scab, but after the scab fell off, there was one stitch left.
 The person who removed the stitches wasn't the doctor who performed the surgery, it was a nurse? Regardless of their skill level, if there's a stitch left, can I just say "oh, that's how it is" and move on
 ? Or was it a huge mistake?
 I'm not that upset, but if I found out later, it could've been torn or something big.
 I'm  going to ask the regulars and call tomorrow.
 I wonder how the regulars would react.