What would cause visible white flecks in urine? ive had this since i was a child and no doctor had ever seemed concerned?

Likely crystals: Your pee often contains urate crystals which reflect the breakdown products of protein metabolism. Crystals will often reflect light in a way they could appear this way. They would be more prominent in more concentrated specimens. You have likely had occasional urine analysis in the past ( standard test) & if so these would be considered a normal findings.