Lnd1986

I started my period on May 2nd, 2014 and it lasted only 3 days ,on that following Wednesday may7 I had cramping and spotting with a blood clot. This was happening everyday with also pressure when I peed with no pain, just pressure. Now I am having strong cramps in my lower abdomen. The spotting has eased up but I noticed their was a slight pinkish color yesterday. I do not think I am pregnant bc 4-1/2 yrs ago I had a tubal ligation done after my c-section , so that's out of the question but any suggestions on why I am having these symptoms ?