Hi,
Welcome to ehealthforum,
The bleeding could suggest that you had hymen rupture (if this was your first time intercourse). If pre-cum or semen has come in contact with vagina, chances of pregnancy cannot be ruled out (especially if you were during your fertile days at the time of intercourse). Sometimes there can be variation of 5-10 days in your menstrual cycle length due to stress, hormonal changes, lifestyle changes etc. Wait and watch for your periods. If you do not get your periods within 10 days of expected period dates, or if you get abnormal periods, or if you develop symptoms suggestive of pregnancy, you should consider visiting your gynecologist for thorough examination (to confirm pregnancy related changes/signs in body) and blood/serum HCG level test (to confirm/rule out pregnancy accurately). If pregnancy gets ruled out, and if you are not ready for pregnancy, but intend to remain sexually active, consider visiting your gynecologist to get started on suitable regular birth control measures to be protected (after your periods). Be regular with birth control use as instructed. Avoid having unprotected sexual contact.
Take care.