Went to the bathroom -before I flushed I saw what looked like a clot of blood/mucus.

I’m now having really bad lower back pain.

This is my second baby so I know what I’m feeling is NOT contractions. I also wonder if what was in the toilet was there before me, as it was a public restroom. (I always check before I go to the bathroom but this time I was about to pee myself haha)

Worried it could be a kidney infection? What’s everyone’s thoughts?