It’s not necessarily abuse to not react strongly to your child having a minor injury, but that could be a reason why. It could also be you learned to mask your pain to avoid further abuse.

I also have a stupid high pain tolerance (like making it through my vasectomy without anesthesia while only saying ouch under my breath, because my surgeon didn’t believe I could still feel everything), but my mom knew about this from her masters degree and applied it to me.