I had unprotected sex on jan 3rd. i took a urine test at home on jan 12th and it was positive. did i get pregnant on the 3rd or earlier? that's 8days

Sounds early: If your period started exactly 2 weeks before jan 3rd, then that was ovulation day and you have one heck of a hormone pregnancy response and a super-sensitive home pregnancy test! i would lean more toward your having gotten pregnant in december rather than in january, only because i don't believe hpts are that sensitive. Check your dates, and talk with your doc. The ultrasound will tell all.