I Am 21 Years Old And Sexually Active With My

I am 21 years old and sexually active with my boyfriend. I am on the pill. I got my period on the 13 finished on the 18. Then got it again on the 24 and finished on the 28. And I started bleeding again on the fourth. It was brownish. What can be the cause of this? I'm not pregnant am I? I also just recently got a dog and he makes my heart so soft. I figured that might've triggered my hormones.