Thank you for posting your question here I will try to answer it to the best of my abilities.
Many women take contraceptive
pills for months, even years before they decide they want to get pregnant and from what I have seen in my career they usually always manage to get pregnant unless is their some other problem with them.
The best way to get pregnant is by having intercourse on the days when you are ovulating, so when you see your doctor for the prescription for contraceptives, ask him how to calculate the days when you are ovulating.
In case he doesnt know how to calculate them, refer to me and I will let you know.
I hope this answered your question.