Wow, congrats! 95yo & active. If only we could all be like you! So what causes groin pain? Let's get down to basics so that we're all on the same boat. The groin or inguinal area is the crease where your thigh meets your pelvis when you sit down.
A hernia would be the most obvious item on the list. Have you noticed any abnormal bulge or more pain in the area, especially when you lift something heavy or bear down like you're having a bowel movement?
Other things like appendicitis could also present as groin pain but typically starts around the belly button and then migrates down to the right lower quadrant. On the left side, diverticulitis, which typically presents as left lower quadrant pain, could get confused w/groin pain. Both would more likely be associated w/fever and loss of appetite. And unlike a hernia, you can't usually purposefully make either one worse.
Kidney stones can cause groin pain as they descend down the ureter. Infection of the testes or its epididymis as well as torsion (or twisting of the testes which then cuts off its blood supply) could cause pain radiating upwards into the grown.
I suppose a bladder infection could be interpreted as groin pain (although it's usually described as suprapubic or above the pubic bone) but this is usually accompanied by discomfort when urinating or voiding.
Without a rash, it's less likely to be shingles. However, the pain could also be musculoskeletal in nature. Arthritis, whether osteo (from wear & tear) or rheumatoid, could present as hip/groin pain. One of my bigger concerns would be a hip fracture b/c the hip joint is actually in the groin area, not the bone out to the side where we usually point (for instance, what were the results of your most recent DEXA scan?).
As a geriatrician, I'd want to know about trauma (did you fall recently?), infections (any fevers, sweats or chills), change in bowel or bladder habits (you wrote no), blood in stool or urine, along with the usual medical/surgical history & medications, amongst lots of other questions.
Given that you've seen your physician over the last 7 weeks, I'd want to be sure that an xray of your hip/groin/pelvis, a urinalysis, and some basic blood work has been performed.
Hope this helps!