The best advice I ever received was to keep quiet about the pregnancy for as long as I was able (a difficult thing for me since I like to share with everyone). The reason is simple: miscarriages are fairly common. Approximately 20-30% of all pregnancies result in a miscarriage, which translates to one out of three pregnancies. Keeping those statistics in mind, you may want to wait to make sure your pregnancy is viable before telling the world. It's tough enough dealing with a miscarriage emotionally on your own without adding the sympathy and disappointment of family and friends. If you do think you're having a miscarriage, call your doctor immediately. You might need to have medical assistance.
Go ahead and make an appointment with your doctor when you discover that you're pregnant. Typically, doctors will schedule you for your first appointment when you're nine or ten weeks into your pregnancy. From that point on, you will probably see the doctor once a month until you reach 32-34 weeks at which point you will see the doctor every two weeks until you reach 37 weeks. After that, your appointments will likely be scheduled once a week.
From the Doctor's Perspective...Figuring Out Your Due Date
As doctors, we determine the due date, or EDC (estimated date of confinement), calculated on approximately 40 weeks, beginning with the first day of the patient's last menstrual period. Doctors have a pregnancy wheel that calculates this fairly easily. They can also use computer programs. An easy way for a patient to figure out her due date is to use Naegele's Rule: take the first day of your last menstrual period, subtract three months, add seven days, and that should be your due date. We call it the poor man's OB calculator. Interestingly, it comes up to 40 weeks pretty consistently.
If you don't know when your last period was (perhaps because you were breast feeding, on birth control pills, or had an irregular menstrual cycle), then the best way to determine the baby's gestational age is to have an ultrasound.
Sometimes, patients ask us why we use their last menstrual period, rather than the date they thought they conceived or had sex. It's simple really. We've found that it's easier for a woman to remember her last menstrual period than to know when she last had sex. Plus, fertilization doesn't necessarily occur when the couple had sex.
The biggest "lie" of pregnancy is thinking that a baby's gestation is nine months. Actually, the average pregnancy lasts 40 weeks; if it were nine months that would translate to 36 weeks.