Wa'alaikum assalam! Tahniah on your pregnancy! Honestly, booster vaccine during pregnancy is a bit tricky, different doctors have different views, and it really depends on your specific situation. Since you're only 4 weeks and this is important, please call your gynae ASAP before Monday and ask them directly , they know your medical history best and can advise whether to proceed, delay, or reschedule. A few of us mums in my circle had to make this decision too, and most of us just asked our doctors rather than guessing. Better safe than sorry when it comes to baby, kan? Your doctor will consider your Sinovac history and current pregnancy stage, so don't skip that conversation. Jangan risau, you're being smart by asking!