Ahhh at 15 weeks still difficult to say lah, both boy and girl boleh nampak panjang at this stage! The "three lines" thing tu actually banyak mum friends aku pun confuse pasal, sebab angle of scan sama baby position affects how it looks. Best bet is wait until 18-20 weeks bila clearer, or kalau radiologist can confirm better masa next scan, usually they boleh tell you more confidently then. Tapi honestly the waiting game is the worst part, I remember aku keep staring at my scan pic!