I went for an u/s last week and the umbilical cord was in the way. However, everyone has their theories on the sex because of the heartbeat. We were not able to pick up on the heartbeat until week 13. Fron then until week 20 the hb was always 150. It was at 140 last monday during week 20. Today it was at 130. A lot of people say that it indicates a boy since it is getting so low, even my OB doctor agrees, but how accurate is this? Is this just an old wives tale that should be disregarded?