Eh sabar dulu, injection peracang (contraceptive injection) memang effective, tapi ada small chance kalau timing ada issue atau injection tidak betul-betul work sebab anak baru 1 bulan, sometimes hormones still adjusting after birth lah. A few of my mum friends dapat pregnant masa pakai injection jugak, tapi very rare. Best thing is check with your doctor or nurse to confirm injection betul-betul given properly, and maybe do a test kalau you're worried? Better safe than sorry, especially this early after giving birth!