I have been having lower back pain for a few months that i believe is muscular. i am fairly active and i have had some dull testicular pain.?

Worrisome!: It is not fair to you for you to assume you only have a back ache. If you have associated symptoms and especially if they don't normally go together, you should have a thorough history and exam by your pcp or qualified practicioner and get an answer or start of one. There are many things to consider with your history. Some may be benign but there are some worrisome ones as well. Get it checked.

Listen to your body: Musculoskeletal low back pain is one of the most common reasons i see patients. Left alone, muscular pain will get better on its own within 2-4 weeks. If your spine itself does not hurt, and there is no pain or numbness going down to your legs, should get better with cool compresses and gentle stretching. Pain that radiates somewhere else needs looked at. Testicular pain needs examined sooner.