for baby HB, if you look at those print out photos that your gynae gave you for your first visit... actually, the baby's HB, length, how many weeks and days, fluid condition are in there..
Hb starts from 5th week.. and it gets faster as weeks goes till it comes to a stable beat in one of the trimester...
for instance, week 6 is 130plus and can go even faster as 169plus in week 8..
if can see the HB blinking also counted...