Chest infection- cancel Appt before chemo?

Hi I'm expecting to see my neuro oncologist on Thursday but I've developed a chest infection. Not Covid. I've been doing lateral flow tests. Do I need to phone and cancel? I expect the answer is yes. But I do tend to be over cautious so thought I'd post here first. 

I guess I need to call them and cancel the appointment. I'm gutted. I saw this guy once before 6 weeks of radiotherapy. I haven't seen him since. Chemo was supposed to start in December/·January based on what he said then. But now it's going to be a few weeks after this appt. Based upon them ordering the PCV chemo.  drugs.
I get so nervous about appointments. But pouring them off doesn't make it better :(
Thanks