Original Message

You are not on a regurlarly assigned flight schedule.   The FAA made that clear in a 2017 legal intepretation to Moody-Seven Bar Aviation:

The FAA allows infrequent deviations from a regularly assigned work schedule conducted under§ 135.267(c). However, "iftbe pilot's schedule has intermittent periods where the duty time fluctuates from day to day or week to week, the operator is not maintaining a regular work pattern." In such case, the operation should be conducted under§ 135.267(b). Therefore we must stress that if the flight crew's duty time fluctuates on a regular basis, it would not be able to operate under 135.267(c). See Legal Interpretation to Doug Holee, from Donald Byrne, Acting Assistant Chief Counsel, Regulations and Enforcement Division (July 22, 1989).

https://www.faa.gov/about/office_org/headquarters_offices/agc/practice_areas/regulations/interpretations/Data/interps/2017/Moody-SevenBar_Aviation_2017_Legal_Interpretation.pdf

Additionally, it is not you who makes such decisions, it is your certificate holder.  And, they clearly determined themselves to be operating under 135.267(b) and (d), not (c).   Just look at your GOM (cited above) to confirm such important details!