I am 18 yrs old and I have been on birth control for a little over a year now. I wanted to change the schedule of my period earlier, so when I was supposed to take the placebo pills in my last pack I started the next pack after my period began. 

Before my period started my boyfriend and I were fore-playing and he might have cut the inside of my vagina a little bit. A couple days later I started spotting and then my period began. It lasted around 7-9 days when they usually last closer to 5 days. After that I had a brownish discharge which eventually turned to its normal self again and now every so often there is a dot or a single streak of blood in the discharge.

Could the streaks be apparent because of the change in my cycle? Or something else? Please help