Schistomiasis? I think. Deals with this?

Around two years back I had these feeling that something was crawling under my skin. Then I had some urinary tract problem, for which it would feel like a constant pull. A doctor then diagnosed me and said to maintain my hygiene. I changed my drinking water to a more cleaner and healthier source, for which the symptoms were gone. But again all those stared coming back after six months. Though it was not that severe and would happen only if I forgot to take a shower. I did not pay that much attention. But the feeling of a crawl has now increased but I have got used to it. But now as I read about the worm I feel like I need a diagnose. So need help in the process ? Which speciality deals with this ? And etc.