What Causes Blood In Urine Post Intercourse?
Rest and fluids
Detailed Answer:
There is a possibility that you could have had inflammation of prostate or urethra which was the cause of bleeding in urine after sex. Your present discomfort could be related to presence of clots in your urinary bladder, and we call it clot retention.
I suggest you do indeed take fluids, and go to the toilet frequently. Avoid overdistension of bladder. Try to avoid exertion and constipation which could promote further bleeding.Some empirical treatment with alkalinization of urine with syrup citra-alka thrice daily with water after meals might help. Ciprofloxacin twice daily is a good antibiotic for infection of prostate.
If the discomfort in lower abdomen gets worse despite these measures, try and reach the nearest emergency room where a doctor might attempt to pass a urinary catheter which will relieve your bladder distention.
If you previously were passing urine slowly with a thin stream, there is a possibility you could be having a stricture of urethra which might need to be evaluated by a Urologist rather than the medics in emergency room.
Hope I have been of help.