Aww congrats sa twins, mama! Usually around 16-20 weeks pa lang, especially if first pregnancy mo, kaya mabilis mong mararamdaman ang movements, a few of us with twins noticed kicks earlier kasi maraming babies so mas maraming action sa tummy, hehe. Since you're already 17 weeks, baka within the next week or two na talaga, pero bawat mama and baby different pa rin, so kung hindi pa, wag mag-alala. Best to ask your OB during your next check-up para ma-confirm niya kung normal pa rin ang baby movements, alam nila talaga best based sa development ninyo both!