Could Early Menstruation With Headache Be A Symptom Of Pregnancy?

Hello, I am 15 years old. I am on birth control and have been for 9 months now. My last period was January 17th. I have a 28 day cycle. I took my new pack of pills 3 day late. On January 30, I had unprotected sex and my boyfriend and he ejaculated in me. Around February 7th, I started having light cramps. On the 10th, I started having light intermittent bleeding and have had it since then. It ranges from reddish brown to just brown in color. It's definitely not as heavy as my normal periods. My next period should be in the next day or two. Along with the bleeding, I have had headaches, sore nipples, and dizziness. Could I be pregnant??