I'm 22 years old and I had been on the pill since the age of 14. My fiancé and I decided to try and have a baby. I stopped taking my birth control the week after my birthday in August. I had a period from Aug. 24-Sept. 1 Oct. 7-14. Since then I haven't had a period but I experienced light pink/little bit of red spotting last week. I've experienced a little bit of cramping and the worst cramp was when I was lifting a heavy box and some books. Took a pregnancy test (clearblue digital) and I was negative. Can someone help me understand what's going on please?