Thanks for your query.Based on facts you have shared it appears that your semen my be contain g occult blood .Please consult some Urologist
for clinical examination and get following investigations done
1) Routine Urine Test
scanning of the abdomen and Trans Rectal USG to rule out Seminal Vesiculitis or Prostatitis
3) Semen Analysis
to confirm the presence of RBCs in semen.
Further treatment will depend upon the findings in reports.