how many weeks to tell sex on ultrasound
The viability of sperm varies as well, which means intercourse three to five days prior to ovulation may result in conception. Ultrasound dating of conception is not reliable for determining paternity because the ultrasound can be off by at least 5-7 days in early pregnancy. You may have an ultrasound between 18 to 20 weeks to evaluate dates, a multiples pregnancy, placenta location or complications.