I have a red spot between my teeth. i think it is a cut from floss. will it heal on its own?

Yes: Yes it will heal on its own. Just be careful with it for the next few days, don't over floss it & it should get better. If still concerned send pics or see your local dentist. No worries

Usually it will: Give it a couple of days and see how it goes.

Usually: If it is not gone in a week, advise dental visit to assure that nothing is stuck under the gum tissue

Probably: If it isn't gone in 10 days to 2 weeks have it examined by your Dentist