Am i protected if i take phase 3 of my triphasic birth control pill twice, have a placebo week, and then start back with phase one to delay my period?

Yes: As long as you take a pill everyday, you should be fine.

Initially, yes.: You can safely delay your period while maintaining contraceptive effect by taking an extra week of phase three. However, It's possible that the effectiveness of the Pill will be lower in the both the next "short" cycle and the subsequent regular one. Altho I don't recommend it, if you choose to alter your pill regimen, use an additional barrier contraceptive for those next 2 cycles.