Is this my period or spotting?

i had unprotected on the 4th of this month. i don't know if im pregnant and i was planning on taking a home pregnancy test after i missed my period. today i found a little bit of blood in my underwear and i was overjoyed because i thought it was my period and that i wasn't pregnant (i don't want to be pregnant right now) but then i remembered a symptom is spotting... when does spotting occur? am i spotting?