pregnancy?? help im scared

so today is 1/16. i had sex w no condom on 1/2. he didn’t even cum during or after at all. im on the birth control pill called tri-lo marza. i should have my period by now. ive been on the period week pills since 1/13. should i get plan b if it doesn’t show?? my parents don’t know i had sex so i don’t know what to do im only 17 rn.