About 3 months ago, I changed ds's nappy after his nap and discovered a small amount of blood in his nappy. There was also a drop left on the end of his penis. I took him to the doctors and the the doctor was totally unconcerned and said it was quite common in little boys 
. He didn't test his urine for infection but his temperature was normal.
It didn't happen again so I believed it was one of those things, except it now has happened again. The amount was probably less than before but should I be worried and get him seen again?