Hello dear
Understand you concern
bleeding after intercourse is most common complaints among girls.
In majority case it is not serious and will go on its own.
I think it is due to vaginal infections or rough in your case
Following are the causes of bleeding after intercourse
Infections in the vagina: yeast, chlamydia,
gonorrhea, Trauma to vaginal wall (If penetration without lubrication),
Atrophic vaginitis due to lower estrogen levels
Bleeding from cervix (As it contain superficial blood vessels), endometrial/cervix dysplasia,
endometriosis.
If it will not stop or will occur next time.
Please consult the gynecologist.
Do your hormonal profile like: estrogen,
progesterone, FSH, LH
To exclude cervix cause do PAP smear test, endometrial biopsy
Screening for STD infection: swab test, PCR, Gram stain, NNAT, Cell culture
Advice are below:
Use lubricants and condoms during sex
Insert penis when the vagina get fully wet
Maintain hygiene before and after sex and urination
Avoid sex and douching till you get better
Wear pure cotton loose inner wear
Antibiotics: single dose of azithromycine, flucanazole and tinidazole
Use liquid base lotion that contain vitamin and minerals
If not resolves take proper treatment after diagnosis
Hope this may help you.
Wish you good health.
Best regards
Dr. Sagar