Haha alam mo yan, ganyan talaga ang ultrasound sometimes, especially kung maliit pa ang baby or kung mahirap ang position, medyo unclear ang results! A few of us moms experienced the same thing where the tech said 50-50 or uncertain, tapos yung iba naman nag-confirm na girl na talaga on the next scan. I'd say wait for another ultrasound around 18-20 weeks kung gusto mo ng clearer answer, or ask your OB kung pwede na i-check ulit next visit, sometimes mas visible na talaga sa later scans. Pero honestly, basta healthy baby yun ang importante, no?