I don’t mean to sell out 3D ultrasound, but using a very modern blood test it is possible to know your baby’s gender as early as 11 weeks. The Harmony Prenatal test as it’s called is drawn at 10 weeks, but the results typically take a week to get back. This method costs $200 with insurance, but without insurance may cost many hundreds of dollars.
There is one 3D ultrasound place near Miami which guarantees gender as early as 12 weeks, however it comes as part of a bigger, more expensive ultrasound package ($200 for 3 visits any time in your pregnancy). The same place lets you come for a single visit as early as 14 weeks. By 15-16 weeks most 3D ultrasound places around Miami will show you the baby’s gender. Whether they guarantee it varies by location.
Contrary to popular belief, a 3D ultrasound does not show the gender any clearer than a good 2D ultrasound system. That said, it may be more convincing for you to see the genitalia in a 3D ultrasound.