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.
As BPH progresses, it can lead to enlargement of the prostate gland. About half of men with BPH go on to develop an actual overall increase in the size of the prostate. As BPH progresses, it can squeeze the urinary tube (urethra), causing urinary symptoms.