Hi, I am 21 years old and since yesterday my nipples have been soar and I had a very bad episode of stomach cramps in my lower abdomen. It slowly crept up on me and only lasted about 15 minutes but it slightly hurts today. I had unprotected sex the last few days of my period about 3 weeks ago and again a week ago with a condom. I finially got my birth control refilled from the health clinic and I've been back on it for 3 days. I took a pregnancy test today but it came back negative. I am really confused of what it could be. Any advice here?