Hi Doc... I had my period on the 16 September and I had unprotected sex with my bf between 26Sep -1st Oct. My cycle is 25 days and up till date my per?

Pregnancy. Sounds like good timing for a couple trying to conceive. If not actually trying, you may take comfort that only 70% of couples get pregnant the first year. Use contraception. Check a pregnancy test, now and then a week after the expected period.
Fertility. you are most fertile approximately 12-14 days after the start of your last menstrual cycle. Unprotected intercourse is a sure way to get pregnant or acquire an STD. Time to see your GYN for BC pills and a pelvic exam.