I was having sex with a female of an unknown hiv /std status. i did not use protection for the first couple of strokes but quickly put one on after. am i safe?

This depends primarily on your partner's sexual lifestyle. If a close friend you know well, and not with multiple partners, your risk is low. If she is a sex worker or has many partners, of course it's higher. Short duration of unprotected sex probably reduces the risk, but only a little. If any doubt about her sexual safety, get tested for gonorrhea, chlamydia, syphilis and HIV (but no others).

Unprotected sex sex for any duration is unsafe. Get checked and avoid it in the future.