Hello,
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First of all missed period and spotting indicates the possibility of pregnancy and if you have been having unprotected intercourse then high chances are there.
Now bleeding after intercourse suggests underlying issues as cervicitis,dysplasia,abortion,polyps,endom
etritis etc.It would require a pelvic examination and evaluation to rule out the cause.
Kindly visit a Gynaecologist for evaluation and precise diagnosis.
Take care!