I Had A Circumcision About 16 Days Ago...half Of The

I had a circumcision about 16 days ago...half of the stitches have fallen off but some remain. They also cut a big part of my frenulum and there is a black zone there filled with stitches. It hurts when i urinate a little. How long will it take for my stitches to fall off (even the ones on my frenulum). I'm 16 by the way.