Hi afreen and thanks for bringing your concern to the EmpowHER community.
When we have pain it is the body's way of letting us know that something is abnormal and needs attention. This is especially true when the pain is described as "severe" at times, which you have done.
You need to see your healthcare provider for an exam and diagnosis. You may need both a physical exam as well as an imaging test, such as x-rays or ultrasound, to see what's going on and causing the pain. There are multiple conditions that could cause this pain, and it can't be diagnosed by someone on the Internet.
Please let us know what you learn after your appointment as the information could help others.