Unexpected bleeding???

My last period was June 23-26th. On the 26th I started taking birth control pills and was on them for maybe a week I missed my pill on June 2nd and that night had unprotected sex and let my boyfriend finish in me. I left the next day for a trip and honestly haven't taken my birth control since I've been out of town I forgot it since I've been with family. I'm due to start ovulating tomorrow (July 7th). But yesterday (June 5th) through today (6th) I started bleeding. At first it was dark brown spotting now it's a light flow between dark red and brown to dark brown. I'm not sure if it's the birth control, implantation, or anything else? Any thoughts???