what does dis mean?

i had unprotected sex n about two days later i started to get a brownish kinda bloody discahrge that had no smell…but mostly brown wit a lil blood…at first i thot i was gonna start my period but i didnt…it got a lil havier(enuf to wear a pad but not enuf to soak it or like a regular period)its much lighter then a regular period n still mostly brown after two days…some say it can be implantation bleedin n some say that it might just be old blood comin out but they say it only happens after ur period…i have not gotten my period yet n dont kno wat to think…n if i do want to or end up take a pregnancy test how long should i wait…should i just wait to see if i start bleedin more or if it just stops…i need answers please…16 years old n have no clue…this has never happened except when i had a misscariage but that was veery painful…this time the same thimg is happenin but no pain…just a light brownish bloody discharge…so pleeeeeaaaaasssseee help