Is A Sudden Bruise Over A Pacemaker Site Without Pain Cause For Immediate Concern?

Male aged 79. Pacemaker installed 10 yrs ago. Checked twice a year. Kicks in at 45bpm. Operating 10% of time and battery ok at last check-up. This morning, for the first time, I have a new purple bruise covering the PM . No discomfort. Should I act immediately or wait and see ? Yesterday I wore a heavy rucksack for 40mins (not for the first time) Straps press on the area but this has not caused bruising before. Also thought I may have laid awkwardly overnight. I wondered if the bruise was a known symptom of something unfavourable.