Uy, ang ganyan talaga kasing-confusing na situation, sis! Honestly, since you're on pills for 7 months and suddenly may spotting, delayed period, pero negative pa ang PT, I think kailangan mo talagang mag-check with your OB to rule out what's going on, could be pill-related, hormonal, or something else na kailangan tignan in person. A few of us mum friends have had weird cycles din from birth control, pero 19 days delayed is worth getting checked out para malinaw talaga, lalo na kung may pregnancy symptoms ka pa. Don't stress too much in the meantime, pero schedule that appointment soon ha?