Urine with blood ONLY,no infection no leaking of protein

Im 19, So a kidney specialist told me that it is iga nephropathy without biopsy and after that i had stomachache so i went to a general clinic and the general doctor diagnosed me with stones with just a simple urine test.So who should i trust? and my urine sometimes do come with bloody tissues. and this has been FOR months, more than 3 months, i suspect it is type 1 diabetes but I did not lose weight, my appetite is normal and doesn't have any major changes. TYPE 1 diabetes normally occur very fast. the urine test came out only blood, no urine, no protein or cretinne.