Need To Know If I'm Pregnant ? So Me N

Need to know if I'm pregnant ?
So me n my bf had protected sex so I thought , he told me he took the condom but he's uncircumcised and there was no cum present n he put the condom back on but lately my lower back hurts n my breast seem to have grown ? Could this be from just starting to have sex or could I be pregnate . I had sex last sat. Or sun