Many think of it as 'sticking.' implantation in humans always occurs when the embryo is between 6-7 days old. A very popular concept on the internet now in 2012, 'implantation bleeding, ' is speculative and mostly not useful.
Also, urinary stones can form in the bladder lining due to an accumulation of debris and chemicals. Broken blood vessels can cause blood in the urine, often because of torn or enlarged veins on the inner surface of the prostate. Blood in the urine also can be caused by the sudden stretching of the bladder wall.
BPH causes enlargement of the prostate, which may cause troublesome symptoms. BPH is more common as men get older. The urethra passes through the prostate gland, so men may have problems urinating if the enlarged gland restricts the flow of urine.