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.
How soon can you hear a baby's heartbeat The baby's heart beat can be seen on an ultrasound at 7 weeks, and if you are slim... Can you feel the baby's heartbeat as soon as it forms? You'll be able to hear the heartbeat with a stethoscope at around 20 weeks, but... How soon can you tell if a baby doesn't have a heartbeat?