Aw, kakaworry yan talaga, lalo na pag regular ka talaga normally! A few of us dito sa group had the same thing, 10 days delay with negative PT, at iba't ibang reasons pala why, stress, hormonal changes, even slight infections kaya medyo late ang period. Best talaga na mag-follow up sa doctor para makita kung ano talaga ang nangyari, especially if you're usually very regular, para ma-rule out any health concerns at ma-ease ang mind mo. Hang in there, mama, kaya mo yan!