al-Quran says that a woman is pregnant for 9 lunar months and 10 days. but it doesn't mention when it should be started. modern science considered 9 lunar months and 10 days or 40 weeks starting form the last menstruation make it 280 days while 38 weeks (266 days) from the day of fertilization. in Malaysia, doctor usually takes 40weeks to calculate the EDD (estimated due date) by assuming that the conception should occurs in week-2 (nobody knows when the ovum is out to meet the sperm,exactly).
however, in medical world, mature baby is considered if he is born on 37th week up to 43rd week from the last menstruation. usually doctor will advise the mother to get prepared 2 weeks before EDD.
however, the length of pregnancy depend on many factors. usually the first one could be longer. even, few than 10% birth occurs on the EDD while 50% is within 2 weeks of EDD. multiple pregnancy (twins) also contribute to early birth. and it is multiplied if the babies are triplet or quadruplet. for this kind of pregnancy, the EDD might different than solo pregnancy. it is because, at certain limit, uterus can no more stretch, since multiple pregnancy already carries more than one baby, usually at certain week, the babies' weight is more than full term's solo pregnancy. this tend to urge the mommy to deliver early.
baby, you are approaching 10 weeks. mommy have another 30 weeks to embrace you. i hope you'll become stronger as we are passing the first trimester, in the next 4 weeks. rest here soundly my dear, don't rush to get out before the right time!