Two weeks ago i was put on anti biotics for hematospermia. yesterday i had sex there was blood at first then normal sperm. now its back to blood why?

There are many caus: The following is from WebMD: this covers a lot of causes to consider. Infection and inflammation. This is the most common cause of blood in the semen. Blood can come from an infection or inflammation, in any of the glands, tubes, or ducts that produce and move semen from the body. These include: Prostate(the gland that produces the fluid part of semen) Urethra (the tube that carries urine and semen from the penis) Epididymis and vas deferens (tiny tube-like structures where sperm mature before ejaculation) Seminal vesicles (which add more fluid to the semen) It can also come from an STI (sexually transmitted infection) such as gonorrhea or chlamydia, or from another viral or bacterial infection. Infection and inflammation are the culprits behind nearly four out of every ten cases of blood in the semen.