I’m not saying all stab wounds are worse than all periods. I sliced my finger with a pocket knife once and am fairly confident it was not as bad as period pain. But in general, the average pain and seriousness of being stabbed with a knife is going to be greater than the average pain and seriousness of having your period. The simple fact that while having your period is almost never fatal (and usually limited to societies with poor sanitization combined with “menstrual hut” practices), compared to stab wounds which are about 10-15% fatal, supports this.