What Causes Cramping Before Periods, Spotting And Sore Breasts?

Last month my cycle came on time like always but it only last for 3 days. I hve been cramping for 7 days now and my cycle doesnt start till the 13th. On Tues March 6 I had i had some spotting just when i wiped for about 6 hours. Now I am not cramping as mch. But my breast during this whole times have been sore, especiall at night and my nipples get hard fo no reason. Am I pregnant?