God answers prayers based on His will not ours. The question you have relates to the types of prayer available to you. There is structures prayer, like a Novena that requires nine days of prayer, and usually nine days of Mass attendance for your intention. This is great because you approach God in a approved devotion tied to the Liturgy of the Church. Then there is private devotions ;like Rosary or Saints prayers, and your own prayers. God can answer all these types. Jesus said to Knock, and the door would be opened too you. But, sometimes it takes more than one knock. The Four Living Creatures around the throne of God pray the same prayer over, and over in Revelation!