Honestly, most airlines allow pregnant ladies sampai 36 weeks, but 17 weeks should be fine, tu biasanya masa paling okay because morning sickness dah settle sikit and you're not too big lagi. Better check with your doctor first tu, especially if ada any complications or if you're flying long-haul, because dia boleh advise based on your condition la. A few of us in my mum group travelled during second trimester without issues, tapi everyone's pregnancy different kan, so best to get the green light from your gynae before book the flight!