Question Sword collision phsyics

I'm prototyping a sword fighting game, and I obviously need to detect when swords collide. For prototyping purposes, collision for the swords is always on. The swords have a box collider with IsTrigger true, and RigidBody with IsKinematic true.

This works out great, but not all the time. Right now I'm playing a swing animation against a stationary sword prop for collision development.

In the video below, you can see the yellow lines are drawn when OnTriggerStay is called. I also tried it in Update after using OnTriggerEnter to enable the line drawing and OnTriggerExit to disable it. I get the same results.

I get what's happening. OnTriggerEnter isn't being called because the sword doesn't collide inbetween frame updates.

My question is, how can I do a sweep detection between the last position from the last frame, to the current position in the current frame? So I can catch these instances where the sword never collides from one frame to the next.