I was urinating & a small dried-up fleck of blood fell in the toilet. it looked like a chili pepper flake. i touched it and it dissolved - it was blood. my period is due today but i don't think this was it. what can it be & chance of bladder cancer?

Passing blood in your urine has to be investigated. However with an impending period we can't be 100% sure this was hematuria. Continue to observe for blood in urine but you'll have to separate vaginal blood from urinary blood. You could get a clean catch urinalysis with a microscopic examination if the sediment to check for microhematuria after your period is finished. If this is normal, no worry