So, you don't have a last period date to go on, or you're cycles are irregular enough to not know which end is up. How do you know how pregnant you are? Is ultrasound the last resort, the only way? For so many women it is, and many doctors insist on routine ultrasound when there isn't a period date to go on. But for those opposed to ultrasound (or for those just wanting that first pregnancy challenge) there is another way.

First of all, dating a pregnancy by ultrasound isn't perfect.

The farther along you are, the supposedly less accurate the dating of your baby is. If you're seeing a doctor or midwife with protocol about how many weeks they can let your pregnancy go (for many it isn't much past 40 weeks), then you don't want to take the chance that your due date is incorrect. You could unnecessarily face pressure about induction, or other issues that concern doctors about “postdate” pregnancies. On the flip side, if your due date is put too early and you are pressured to induce for whatever reason, you could wind with a preterm baby, which is no fun either. The bottom line is this- it is worth it to you to put together all the clues you can about your own pregnancy and conception. Here are some ideas to help you figure an accurate due date. Keep in mind that this often requires patience, because some of the “signs” aren't perceptible until a little later in pregnancy.

- Last bleeding, to determine if it was a normal menstrual period or lighter bleeding which may have been implantation bleeding. Plus, menstrual history in general, length of cycles, etc. Even if you know nothing about charting your cycles, anything you might have noticed about your body, along with any suspected dates of conception.

- beginning or ending of any pregnancy symptoms like nausea, vomiting, etc.

- date of any pregnancy tests taken and results (most tests positive at about 4 weeks pregnancy)

- whether your baby's heartbeat can be heard with a fetoscope (usually not until about 16-17 weeks if you've had a baby before, not until almost 20 weeks if you are a first-timer)

- when your baby's heartbeat can be heard with a Doppler (as early as 9-10 weeks if you've had a baby before, a few weeks later for first-timers)

- measuring the height of your uterus, although this can vary from person to person and isn't really accurate until about 20 weeks. Compare to previous pregnancies if possible.

- cervix will change and soften between 6-10 weeks and will be visibly purplish upon exam!

- how your uterus feels, from the outside (can feel it start to protrude out of the pubic bone at 12 weeks) and the inside (feels larger than normal by 7 weeks).

- your report of any fluttering, or fetal movement. The type of movement can help determine how far along you are as well, as kicks come later when bones are developing and getting stronger.

You can always resort to ultrasound later if there are facts that just don't line up or if anything seems unusual for the date you have.