My Periods Is Due On Dec 19th N Dec 13

My periods is due on dec 19th n dec 13 my bf ejaculated over me when his penis was between my bum. I didn't realise at first but then I wiped myself and then he wore his condom and we did it again. I don't know whether his semen trickled down to my vagina. Im thinking if I should take a pill. But want to know the chances of getting pregnant at this stage. Please help im 34 n all diz happened in a haste.