What kind of mileage have you done in the past? Better to nudge yourself along gradually than make a huge jump. You have a lot of time to develop, why risk sitting out for 3 months with a stress fracture? The actual time a serious bone injury will cost you may be more like 6 months, as you have to very slowly rebuild to get back to your previous level of training.
Look at your current mileage and set up a reasonable progression from now until your senior year. You run 50 mpw now? Build to 60 this year, 70 next, and 80 in your senior year. Experiment with how you structure it. Find out what keeps you healthy and makes you feel the best. Keep in mind you generally want to hit your maximum in the late summer and winter, depending on how your racing is scheduled.
If you run 80 mpw during senior year of high school and can stay healthy and not feel way over-tired (and hopefully run fast), you will set up yourself up really nicely for college.
While some coaches salivate over the untapped talent of a 4:12 guy running 40mpw, a lot do like to see you can handle real volume and not break. A 9:10-15 guy running 80mpw in HS can be developed into a really solid asset in 10k XC, mostly bc they can handle the training.