What Causes Blood Discharge In The Semen?

when ejaculating , at first I noticed some blood in my sperm, then it became straight blood streaming from my my penis for two or three seconds . I have previously had blood in my sperm, had several tests they found nothing, this was aprox 4 years ago . I am a 54 year old male , should I wait to see if it stops on it s own , or should I seek medical assistance now ?thank you , Clay My e-mail is YYYY@YYYY