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.
The babies heart beat develops at the fifth week of pregnancy. By the 12th week of pregnancy, you may be able to hear the babies heart beat. This can vary by days or even by aâ¦ week or so, as well as how high-tech the device is. So don't be alarmed if you dont hear it on the first day of week 12!