Eh, walk-in prenatal care memang quite hard to find, most clinics need appointment dulu sebab doctor schedule packed sangat, especially di KL/Selangor area. Better call ahead ke private clinic or government hospital maternity ward, derang usually can squeeze you in same day if urgent, but kena confirm dulu lah rather than just show up. Try calling KL Hospital or Sungai Petani Hospital maternity section, derang usually more flexible with walk-in compared to private clinics, but honestly depends on how busy they are that day.
Centre, a few of us managed to squeeze in walk-in slots pagi-pagi, or sometimes they can fit you in same day if it's urgent. Best check their hotline direct, or drive ke private hospital nearest you and tanya reception kalau ada slot available harini, better than sibuk-sibuk travel sini sini. If it's really urgent, go to any government clinic nearby (klinik kesihatan) or hospital A&E, they won't reject pregnant mums. Hope you get sorted out fast, take care!