My prescribing doctor reviewed my supplement regime and advised...

My prescribing doctor reviewed my supplement regime and advised me to not take fish oil on the days of my PPS injection. Fish oil has antithrombotic properties.

I also do contact sports, and he also advised me to refrain from those activities on those days too.

He also referred me for blood tests midway through and at the end of my course, to look at coagulation factors.

These are prudent measures, and in no way difficult to comply with. No issues ever turned up. There may be conditions where closer attention is needed, but I would think you could juggle dosing schedules for people on blood thinners over the few weeks of treatment.