These polyps may follow a bout of ulcerative colitis or Crohn's disease of the colon. Although the polyps themselves are not a significant threat, having ulcerative colitis or Crohn's disease of the colon increases your overall risk of colon cancer.
This interactive Due Date Calculator will help you estimate the date your baby will arrive. Pregnancy usually lasts 280 days (40 weeks) from the first day of the woman's last menstrual period. This calculator is a general guide: every pregnancy is unique, and sometimes babies arrive sooner or later than expected. Always talk to your health care provider about your due date.
40 weeks from the first day of your last period.  as said by brain child is correct. that is how the due date is calculated. However, sometimes babies come early and the actual time spent in the womb will then vary. Usually a baby born after 37 weeks will have no health issues etc so it is a safe time to deliver.