how can i stop stressing ??

i was on birth control and me and my boyfriends condom broke on the 28th of november . out of total freak out i took a plan b 30 minutes later . i am 17 days late . i took a pregnancy test when i was eight days late and it was negative . i had some light brown discharge yesterday , and after sex ( with no pain ) i had some bleeding when i wiped myself off . i have also been having period like symptoms for a week . i have been stressing so much as i am way too young to be pregnant . how do i stop stressing and how do i make my period come ?? my birth control period isn’t until the 16th of this month . do i just wait until then ?? do i need to take another pregnancy test ??