### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
Hello Dr. Grief,Me and my husband are planning to get pregnant and are planning for a specific date for our child to be born around Sept 30, 2012. What will be a good time to conceive if my menstrual period starts around the 29th and has a 30 day cycle?

### output:

Hallow Dear, The duration of pregnancy when counted from the last menstrual period is 280 days or 9 calendar months and 7 days. In fact the egg is released (ovulation) 14 days prior to the next expected menses; i.e. if the cycle is of 30 days the egg will be released on day 16 of the cycle. The egg has 24 hours life while the sperms are active for 72 hours. Hence, the conception can happen about a week around the day of ovulation. Considering this, for practical purpose we consider 2 weeks less from the day of ovulation (or conception). So the pregnancy precisely is of 266 days. However, for the sake of convenience, we calculate it as 280 days from the last menstrual period date. Considering these facts, if the delivery date is to be expected on September 30, the last menstrual period date should be 23 December. (Would you be having it then?) Now your cycle is of 30 days period. So the expected date of ovulation should be 07 January. Hence, if the conception takes place on 07 January, the due date of delivery would be 30 September. The hitch here is that you should have ovulation taking lace on 07 January. Moreover, we have noticed that all the pregnancies do not last for 280 days. The delivery can take place any time between 3 weeks earlier to 1 week later than the expected due date of delivery. Keeping these facts and calculations in mind, you may plan your sexual relations accordingly. I hope this will help you.