I'm on the birth control tri previfem (norgestimate and ethinyl estradiol). i took one 12 hours early, do i need another form of birth control and how should i take the rest of the pack?

Early better > late: Management depends on timing of cycle. You could take a second pill at the regular time, and then continue daily, which will cause your period to come 1 d early, and resume next cycle BCP one day early. If late in the cycle, you would be fine to wait for the next day's pill, and you may have some spotting, but risk is low. Additional protection is always the safest.