If your groin hurts, it wouldn't be a femoral stress fracture, but a femoral NECK stress fracture, which is one you definitely don't wanna mess with,
But for what it's worth, I had a femoral stress fx (in the shaft, not the neck, but very high up towards the neck), and I passed the fulcrum test with flying colors. I hear it's only really accurate for distal femoral stress fractures. Hop test also not as accurate for a more proximal fracture (only really good for feet, lower legs).
Could be psoas strain. Or rec fem. I'd look at one of the hip flexors. But if there's no pain with passive movement, then I'd be more concerned about bone. If it's muscular/tendon, you should have symptoms with non-weight bearing movements as well (drawing leg to chest, for example).
Good luck.