Mine was bang on 140 bpm at 16 weeks so gave us no clues. Had my 20w scan on Friday and........it's a boy! This fits with me having zero sickness and craving cheese/salty foods. Bump seems to be low and all out front too. On the other hand, the nub on 12w scan was definitely straight (but did have some 'thickening' at the end which apparently indicates boy) and his skull is round not angular.
my DS heartbeat always suggested girl, that was wrong! Do you think the food cravings are an indication for anything? DS I craved anything juicy and fruity in the first trimester, this time (9 weeks) I have done nothing but crave carbs and salty food!