im i pregnant???what going on???

i had my period on sept27 and i had unprotected sex with my bf on 10/6 & 10/17 my peroid came on october 20 now on 10/31 i had a browish discharge n when i wipe myself its very light pink next day wipe pinkish still and when i put on a pad there is no blood and now same pinkish blood to dark brownish red blood..what does that me help pls i dont know whats going on...thank you