Salam! Biasanya bleeding lepas pasang IUCD boleh berlaku a few days to a couple of weeks, tapi kalau hari kedua dah penuh pantyliner macam tu, memang agak banyak sikit. Setiap orang lain-lain, ada yang spotting je, ada yang heavy macam period, so far normal range lah, tapi since this is your first time I'd suggest check with your doctor atau nurse clinic yang pasang, they can confirm kalau bleeding pattern you macam nih okay ke ada issue. Better safe than sorry, kan, especially recently pasang.