Is there a chance i could be pregnant?

Okay, this is gonna be hard to explain but on the 6th of this month I had sex and some of his semen was on his finger and he stuck his finger in me MULTIPLE TIMES with semen on it, then on the 8th I had sex with the same guy and I believe a little bit of semen got in me.. my breast have been very tender and feel heavier than usual a tiny bit? and I right now I’m having lower back pain a little bit.. I’m supposed to get my period soon but I’m scared. Please help!!