Been taking ocp yaz (drospirenone and ethinyl estradiol) placebo since saturday just gone and still no period and not pregnant, should i start a new pack or keep waiting for period?

Re-start pill now: It is common for low dose contraceptives to NOT produce anything other than slight brown period "bleeding" or no "bleeding" at all to remind you when to start the next pack. As long as you took the pill everyday as directed, the pill "period" is only hormonal withdrawal bleeding, and denotes only the aforementioned need to re-start the next pack.