My daughter was once a child "model" in a fashion show of a new line of kids' clothing. The manufacturer's rep was there to answer questions. She told me that cotton clothing shrinks in the last 1/3 of the drying cycle and, if you don't want cotton clothes to shrink, you should take them out of the dryer when they are half dry.

Ever since then I dry clothing on "low" for 2-10 minutes, then hang everything. Bonus: almost all items require no ironing when handled this way. Good luck with your new jeans!