He fingered me, there might be some precum on his fingers

im terrified. im only 15 and ive sworn to myself that i will not have a penis inside of me until i graduate, but i do allow some sexual things between me and my boyfriend. on a tuesday, he peed and then a little later we started doing stuff... he rubbed his penis on my vagina (my vulva and labia) then he licked my vagina and started fingering me. im pretty sure he hit my cervix. my question is this: could i be pregnant if there was precum on my vulva and when he fingered me? what is the risk of prgnancy? also, my period is scheduled for the 13th, ten days after the "incident". if i get my period and the pain is as unbearable as it usually is, could i conclude that im not pregnant? or would i have to wait until my next period to be sure?