| It all depends on her "cycle." When was her last period? When did she ovulate?
Are you ready to be a father?
I may, and most likely will, get criticism for this, but here goes....
If you are not ready to be a father and face all of the consequences then you should reconsider having sex.
Birth control, no matter what kind you use, is not 100% effective.
I don't know your age, but you should be considering your future and your priorities. Because, if she does get pregnant before you are ready to help emotionally, physically and financially, you are stuck with something that will not go away with time.
In an honest answer to your question.... there is no way of knowing without knowing her cycle. But you can bet your bottom dollar is is about 50% |