Foetal Heart Beat can shown in ultrasound scans as earliest as 6 weeks. In the ultrasound scans You can see a bulge where the heart is and a bum which will become head and brain of the baby.
The heart beat can range anywhere from 110 to 160 BPM (Beats per minute). Foetal Heart beat should not be either too high or too low at 6 weeks of pregnancy. If it’s too high you should consult you doctor as soon as possible
In some scenarios, the heartbeat won’t be detected so you may be asked to come for repeat scans in 5-7 days timeframe so they can measure the crown length which would indicate the gestational age of the Foetus.
Foetal Heart Beat generally increases from 5th week of gestation and around 9th week it might be much higher and after 13th week it gradually reduces and would be in the range of 110-160 BPM, if your baby has a high Foetal Heart rate during 9th week you need not worry about it