My advice to you -- See your dentist!!! I had the exact same thing happen to me a couple months ago & I could not get the stupid piece of floss to budge. So I figured the heck with that & left it alone. Only about 1 week later that whole side of my mouth swelled up and my jaw and gums became sore and bloody.
I went to the dentist and was told that the tiny little piece of floss that was stuck had caused an infection in my mouth. I had to get a shot to numb it up and the dentist had to dig around my gums with this sharp metal thing for like a half hour to find the floss. In only ONE WEEK it had embedded itself under the gumline & caused a HORRIBLE infection. My dentist told me if I had waited any longer I would have ended up with a whole slew of complications. Rule of thumb... if you cannot remove the floss, go to the dentist.
It is not worth the pain and agony of what I had to go through!!!