antibiotic on BC??

i’m on the new mini pill Slynd. this is my first month. i take it every single day at the exact same time. i’m on my period rn even tho my placebo week is in like 4 days. yesterday i had unprotected sex with my bf and he pulled out every time. today i went to the doctor because my tonsils were super swollen and it hurts rlly bad when i swallow. he prescribed me antibiotic pills. i asked and he said they could possibly weaken my BC because every antibiotic may affect BC in some way. I was just wondering if i would be okay to start the meds the doc gave me tmr or if i should wait like three more days (making it 5 since sex) so ik all the sperm died. i just want to know the possibility of my Bc failing at this point and me getting preggo.