i’m scared

my boyfriend and i had sex yesterday, several times. at first we used a condom then took it off and came on me, and we took a shower. but later we had sex again without a condom and he didn’t come but could his pre-cum have cum from earlier? what are the chances i’m pregnant? my period is supposed to come in two days and i’ve been breaking out and my back hurts and i’m more hungry so i’m not sure if those are just period symptoms or pregnancy symptoms.