The Pregnancy Calendar: Due Date Details

hi, thank you very much for sharing us such information. as a future mother i find this app is very important. it helps to calculate everything. beginning from the first weeks till the due date, i know all important events and it's just wonderful. to my mind a modern world makes our life more easier. I'm so glad i could be closer to my babies. 
Pregnancy is the time (usually nine months) during which a woman carries one or more offspring until delivery. Childbirth usually occurs about 38 weeks after the conception, or about 40 weeks after the last menstrual period. The actual length of pregnancy depends on various factors. For example, the first pregnancy tends to last longer than subsequent pregnancies. Fewer than 10% of births occur on the due date; 50% of births occur within a week of the due date, and almost 90% occur within two weeks of the due date. so the calendar will helps to define the due date