I noticed the other day when I was done shaving I had a small razor bump (I’m still using the gillette fatboy I got as a birthday gift a few years ago LOL). I usually always stretch my skin when I’m shaving no matter what but on that particular day I only did on my last against the grain (ATG) pass. what I’m wondering is if that was what cause the bump to happen. Could not stretching in the 1st 2 passes have resulted in me having accidentially overstretching my skin in the last ATG pass? I almost never have this problem when i do stretch the skin through all three passes.
Its possible that you got a bump from not stretching but its really impossible for me to say without having seen you shave–there are just too many variables. Everyone will get the occassional bump or ingrown. Its when you start getting them consistantly that you have to start looking how you shave a little more closely.