During pregnancy after husband physically relation...

Treatment of bleeding after sexual intercourse:
Well, it should be noted that the treatment manily depends on the cause, so it's recommended to visit the specialist doctorto evaluate your condition and make the proper intervention according to it.  Right now, it's quite obvious that you should keep away from having and to keep you genital area clean and dry as much as you can. If there is bacterial infection, some medicines such as Metronidazole 500mg twice a day for 10 days can be used. Moreover, if there is vaginal dryness, estrogen ointment will be prescribed.

Investigations for diagnosis :
Medical history and clinical examiantion to be done by a doctor including vaginal and cervical examination by spiculum. Complete Blood Count to detect any infection. Pelvic ultrasound to check for any tumours. Urine analysis to rule out UTI. 

Causes :

• Vaginal dryness
• Infections
• Trauma
• Cervical or endometrial polyps
• Fibroids
• Endometriosis
• Anatomical abnormalities
• Others

Recommendation: 
It's recommended to visit the Gynecologist for further assessment and management.