I had unprotedcted sex with my bf last night. i got my period today, but my regular period time is supposed to be two days later. do i need to plan b?

I would: Not all bleeding is a period, so I would get plan B as soon as possible. Might be a good time to start regular birth control as well if you plan on having unprotected sex again and don't desire pregnancy.

Probably not: The likelihood of getting pregnant at this time of your cycle is remote. However, I would encourage you to use a reliable method, rather than depending on plan B, which may fail you.