3 days after my boyfriend came in me, i started getting brown discharge then pink/redding blood for 3 days.?

my period wasnt due for another week so i bled a week early. i told my boyfriend i dont think i am pregnant but he keeps insisting to take a preg test. i dont want to take a test yet because i THINK i had my period, but im not sure. when should i take a preg test. and why does he keep insisting that im pregnant(he tells me not to drink etc) when i told him i dont think i am. should i just take a test? HELPPP i have a crazy bf