Can u get pregnant 8 days before your pregnant or could it just be my period coming my back hurts…

Can u get pregnant 8 days before your pregnant or could it just be my period coming my back hurts and my breast hurt messaged me for more details I don't know what's going on but I had sex on the 26th idk if I could be pregnant I need help. trying to conceive so I don't know if I can get pregnant 8 days before ur period plz messaged me back or comment plz