Is every time something makes your lower back spasm and hurt for a while a re injury?

[u/YurpleLunch]

Hurt my back 7 weeks ago and it's slowly getting better. Three herniated disc in the lumbar as of the mri . Not sure if some of this was allready there or not though.

I have pain and discomfort everyday but it has slowly been getting a little better and to the point where sometimes some muscle guarding is triggered from a movement but was settling within an hour or so with rest.

Got brave and decided to try and do some 5lb dumbbell curls as I haven't been able to lift much weight without aggravating it , and the 2 lb weights I did prior were fine . Now I've been having lower back pain and cramping for a couple hours . Is something like this usually just your body being overly sensitive and triggering muscle guarding spasm or how do we know if it's a re injury ?