Pain in back for 2weeks after diving into swimming pool. will this heal on its own? when should i seek urgent medical attention?

E/R.UC: I suggest an ER r urgent care evaluation- may be muscular; hoever xrays are important and so is a medical exam,

Back sprain...: It sounds like you may had suffered a back sprain while you were diving. This usually heals after a few days. In the worse case scenario may take few weeks. In order to help a faster relief use ice in the affected area for 15-20 mins three times a day. You may also try anti-inflammatory meds if you are not allergic like for example ibuprofen. If not better follow up with your doctor.