The first meaning is 'metre' which is a measurement of length. If the 'm' stands alone it is metre. The second meaning is 'milliâ¦' which means a thousandth. In this case 'm' can not stand alone, we need to know what we have a thousandth of; if it is weight, length or some other thing. Example: mg means 'milligram', a thousandth of a gram. Example: mm means 'millimetre', a thousanth of a meter.
At about six weeks into pregnancy (four weeks from conception), you should be able to see your baby's heartbeat on ultrasound. The typical heart rate at this age is about 100 beats per minute.
Fetal heart dopplers can usually detect your babyâs heartbeat after about eight or nine weeks gestation, although it may be faint or inconsistent at that age. By 12 weeks into pregnancy, the doppler should consistently and audibly detect your babyâs heartbeat, allowing you to hear it sooner than you otherwise would.