Welcome to HCM.
Nothing to worry.
If there is minor injury
or infection of reproductive tract is the possibility of blood after prolonged sex.
As you did your urinary examination and it becomes normal it rules out the possibility of infection.
So only possibility is minor injury to your tract. If you abstain from sex for a week or 10 days it will heal spontaneously and you will be free from your present problem.
If there is persistence of your problem afterwards examine your semen for the presence of infection and go for a culture and sensitivity test and get your treatment accordingly the you will be alright permanently.
Get well soon.