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.
A heartbeat should be visible via ultrasound by 6 weeks of pregnancy. At 7 weeks your baby has arm and leg buds. At 8 weeks, your baby starts moving around around and by 9 weeks your baby has 10 fingers and 10 toes. Between 10-12 weeks you should be able to hear your baby's heartbeat with a trans-abdominal doppler device. And at 12 weeks your baby can suck its thumb! posted 10/12/2010 by sugar&spiceX3.