My bottom front teeth are not in the same position they were when i was 14. they're now slightly crooked. can't tell unless looking. is this normal?

Not wisdom teeth!: As we get older there are natural to get some changes in your bones. One such change is a narrowing of the lower jaw as the canines tip in slightly. This takes away some of the space for the lower incisors causing them to shift and become slightly crooked. See your dentist for more information and if your wisdom teeth fully erupted do not remove them.

Yes, it happens: As we age, the forces of your tongue pushing against your teeth as you swallow tends to push the posterior teeth forward, crowding your lower anterior teeth. At 17 this should be minimal. If you would like to prevent further movement, talk to your dentist about an orthodontic retainer.

Lots of reasons: There may have been minimal contact discrepancies to begin with. Lower jaw outgrows upper. Facial drape changes altering muscle forces on the dentition. A malocclusion will predispose to crowding. Front teeth tend to erupt, and the space they erupt into is smaller. That's why Orthodontists make retainers for their patients. See your Dentist and possibly an Orthodontist.