HI, welcome to healthcare magic
The pain in the right lower back can be due to muscle strain
or spasm(this would tend to be worse on movement and there may be a history of prior excess movement or physical activity), kidney infection
(associated with symptoms such as discomfort on passing urine,fever,abdominal pain
,blood in the urine, smelly urine) , kidney stone (tends to be an intermittent severe pain
), viruses such the flu virus can also be associated with muscle pain
If the pain is still present, increasing intensity then you should consider having it evaluated at an ER or at your doctor's office.
I hope this helps and I hope that you feel better soon