Hi thanks for contacting health care magic....
First infection of accessary genital organs like seminal vesicles , prostate ,
epididymis might be infected that can lead blood in ejaculation....
For that ejaculated Semen send to lab for analysis ....
If shows pus cells then antibiotic given....
If fever ,
weight loss like feature present semen tested for
tuberculosis .....
If needed culture can be done....
USG abdomen will also be helpful....
Trans rectal palpation and
ultrasound will be helpful for rule out prostate cause.
Meanwhile healthy and balanced diet taken...
Fruits more .
Keep alcohol and smoking very restricted.
Consult surgeon with keeping my answer in mind.
Take care