It's extremely unlikely - if your period started on 8th January, you will have ovulated 14 days previously. There's only really a 4 day window around ovulation when you can get pregnant, and if you didn't have unprotected sex then, it's not likely that you could be pregnant.......especially since you have your period!
Anytime you have unprotected sex you can get p/g.
Did you take a pregnancy test? Did you think you were pregnant before you got your period?