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i have tying to concieve for about 6 months. every month is the same thing... i'll be a week or so late ( or so i think) covince my dh we're having a baby, then a week later af comes. my cycleis really irregular, therfore, i don't know when i ovulate and when the best time would be to "try". anyway, this month af came on the 11th. so i went on this ovulation calculator site, and it said the best time to try would be between the 22 and the 26. so, today, just for fun i went back to the calculator, which also had a "due date" calculator. i typed in my last menstral(sp?) cylcle was the 11th. then it gave my the results as being " congrats... your baby while be born january 15, you are 3 weeks pregnant" how is that possible when chances are if i am pregnant, it wuld have only happen within the last 3 days? so, my question is, when the doc claculates your due date, useing the first day of your last cycle,arent they always wrong with how far along they tell you that you are. i'm sorry if this is a confusing, or ridiculous question. but someone please answer if they understand what i am trying to say