my period was last week and i accidentally forgot to refill my prescription for the pill, its been about 5 days since i last had sex.

the sex was impulsive and my boyfriend came in me (i was okay with it). he is nervous because ive missed about a week of the pills. i keep telling myself i still have the medicine in my system but im not 100% sure. its too late for a plan b pill and im worried i may be pregnant. does anyone have any advice ? im scared and not stable financially or mentally.. any help is appreciated, thanks.