I'm having blood oxygen desaturations down to the mid-70s during the night with sleep apnea. is this dangerous or can it wait until i see my doctor in a couple of weeks?

It's quite low saturation but it does not cause immediate complications other than your interrupted sleep (you almost always overcome the desaturation by continued respiratory effort) with sleepiness and drowsiness during the day. In the mean time, you should sleep in almost erect position or put a ball in btwn the shoulder blades so you will sleep on the side then your upper airway isn't blocked.

Have you had a sleep study yet? O2 sats under 80% are considered harmful and it's important to determine how.many episodes occur during the night and if your sat improves to 90 % or.more right away. If so, my sense is that you can wait for your appointment.