Worried about pregnancy! Please read\\need opinions!

Hello, ive recently engaged in butt sex (sorry for terminology it wont allow bad words), i was on bottom (male) female was ontop, she

was laying on me, and i covered the bridge to the vaginal cavity from the butt hole with my hand and shortly thereafter we wiped off

what may have gotten through my hand with a sock (may have sperm on it from previous engagements) now i wasnt worried as it

wasnt even in the cavity, but after intense debate ive began to worry as having a pregnant GF which i love very, very much would be

insanely terrible for our relationship, what should i do? She started Birth Control, ironically, the next day and her period was due today

or the next (9/20). We couldnt get the plan b pill due to money, transportation, and age issue, but in everyones opinion what is my best

option? ive made recent attempts at accessing advice in person from Planned parenthood but you must have an appointment. Please

Respond and help me out!!!!!!! ANY RESPONSE IS GREATLY APPRECIATED! TY!