Should I be worried?

So i recently started a new job about 2 weeks ago and well by the 1st week i cut the side of my nails cause they were digging into my skin a little bit.

About 5 days ago i was taking a bath and i noticed a dark dot on the edge of my nail. By the second day it spread more into a line. Now it looks like this.

I don't remember hitting myself at all but even if i did, would it spread like this after a few days?

Is it an infection? Sorry i know y'all aren't doctors but i don't have insurance and i don't want to go the ER unless absolutely necessary.