Posible bang mabuntis agad after tumigil sa injectable family planning?

Nag due po ang injectable family planning ko , dec 27, 2023. January 2024 dipo ako dinatnan, February 1st week & last week of the month dinatnan ako, March 2024, 1st week nag spotting po ako, 2x magkaibang araw. April 8, dinatnan n po ako, pero 3days lang, ang normal days ko po is 5 days. nagtry na dn ako mag pt bfore April 8, may guhit sya pro parang evaporation line lang... Withdrawal method po kami since January , possible po ba na makabuo kahit withdrawal? Salamat