What can pain right below my belly button during urination mean?

See a urologist. The most common cause of pain during urination is a urinary tract infection. Much more rare, but fitting your description, is something called a patent urachus. When you were a fetus, a tube from your bladder left your belly button to convey your waste to your mother, called the allantois. This usually disappears, but can stay open, with urine collecting below the belly button or even leaking out.