Kenapa period datang lewat? Upt -ve

Sy jenis period regular 8/3/2023 Melahirkan 2month after delivery getting period on 27/05/23 - 2/05/23 (7days) (selang 25d) 28/06/23-4/07/23 (7days) (selang 13d) 18/07/23-24/07/23 (7dqys) (selang 16d) 10/08/23-16/08/23 ( 7days) (selang 26d) 12/09/23-18/09/23 ( 7days) Jangkaan period oktober 11/10/23 29/10/23- Skg lewat 19 hari (2w5d) dari tarikh jangkaan. 23/10/23(late 1w6d) - upt test -ve 29/10/23 (late 2w5d) - upt test -ve