My last period was on October 23rd. I started using birth control for the first time in 10 years on November 3rd. During this whole time, I was having unprotected sex with my boyfriend where he would not pull out or anything. I recently took my NuvaRing out and started spotting pink. The pink would go away and the next day, I was spotting tan. Now today I am wearing a sanitary napkin where it seems to be a period but the blood is extremely dark. Like a dark purple, almost black even. During the past month, I have been fatigue , my breasts and nipples are tender, and during the night I have experience heartburn and indigestion. Could I be pregnant or are these side effects of the birth control???