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.
No Heartbeat at 8 Weeks. The cardiovascular is the first organ system to develop functionally in babies. In between 5 to 6 weeks of pregnancy, the baby's heart starts to function and beats at a rate of 80 to 85 BPM (Beats Per Minute). Starting from that moment, heart rate of the fetus increases 3 BPM each day during that1st month.