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.
An unborn baby has a heartbeat as early as near the end of the first month of pregnancy, during week four or week five, according to the American College of Obstetricians and Gynecologists. This is just two to three weeks after conception.n unborn baby has a heartbeat as early as near the end of the first month of pregnancy, during week four or week five, according to the American College of Obstetricians and Gynecologists. This is just two to three weeks after conception.