Wah, ni memang boleh jadi! A few of my mum friends ada jugak yang datang haid biasa-biasa then lepas tu realised they were already pregnant, sometimes implantation bleeding boleh macam period, especially if flow dia light je. Congratulations on your first baby, by the way! Since you're already 13 minggu, the best thing is to follow up closely dengan your doctor to make sure everything progressing well, sebab sometimes yang macam ni kena monitor slightly more dekat. Kalau ada bleeding lagi or anything feels off, jangan tunggu, go straight to your clinic or hospital. Excited ke for you!