Wa'alaikumsalam sis! Okay, pening dan muntah yang tiba-tiba macam ni, terutama kalau beza dari pattern sebelom ni, please go see your doctor or call your clinic today, okay? Bukan nak scare, but better to check cepat je, especially at 13 weeks. Could be normal pregnancy thing, could be something else kena check, so jangan tunggu lagi. Lepas check doctor sure you'll feel better, a few of us went through similar scares and selepas confirm semua okay je, boleh relax. Kamu okey? Jangan risau, ambil care of yourself dulu.