On period and saw my pee look pinkish. also been having lower right back pain. i only feel the pain when moving a certain way, so it feels like it it could be from how i sleep. is it serious or could this be from period blood?

Nothing to concern, your urine is most often pinky or even red during period time when you look into the toilet bow. Unilaterally low back back, worse in certain position is due to muscular strain or spasm, commonly seen after waking up with a poor posture during sleep or when carry a heavy object with a poor back position within the previous 24 hours.

I dont think your pink urine is related to your lower back pain- but to your period. From your description the pain seems muscular. Use local heat and sit with a pillow to your back. If not better in a few weeks or if you see pink urine when not having your period pl see your MD