I think one of my teeth has moved. can no longer get floss between it, like before. slightly receding gums. has bone loss occurred? should i worry?

Lots of questions: Hard to answer any of them without examining your teeth. Together with radiographs, your local dentist can diagnose any problems you may have and advise you of the proper treatment.

Floss and Bone loss: At age 17, it is unlikely that you have any significant bone loss, without any accompanying serious medical condition. It could be as simple as your wisdom teeth coming in pushing forward against your other teeth making it difficult to place floss in between your teeth. While you may have gum recession, this can be from overly aggressive flossing, using a hard toothbrush, clenching or grinding.

Tight contact?: Or it could also be that your homecare isn't quite proficient enough and you are having tartar build up in between the teeth making it difficult for the floss to get through the contact. have it checked out because if this is the case it actually will have the potential to cause bone loss if not addressed.

Teeth move: Our teeth move to compensate for the wear our Stone Age ancestors had to their teeth. If teeth not ideally aligned, if your bite changes, if you have gum/bone disease, of you have overbite/underbite/crossbite/crowding/spacing or other problems teeth may shift. See your Dentist for evaluation. Consultation with an Orthodontic Specialist may be in order.