Hi Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern...
The source of bleeding after sex is usually the
cervix, enough friction or mild trauma during sexual intercourse can cause some bleeding. so you should use water-based lubricants during sex. Inflammation of the cervix or some other abnormality, most of which are harmless, can also result in bleeding.
As per your 2nd query, Bleeding after sexual intercourse is not a symptom of getting pregnant. You might get pregnant 4-5 days after
menstruation, if no precautions are taken. Do urine
pregnancy test if you miss your next period.
If problem persist visit a gynaecologist
Don't worry you would be fine
Hoping your query is solved.