Your plans have plans of their own. Therefore, it's best off to just go with the flow.
If you expect everything to go just as you have designed for it to, then you really have everything to lose.
Just say, for example you plan your wedding day. The weather forecast says it'll even be sunny in the shade, but then on the day it begins to rain. Do you complain? Or think come what may. I'd say it'd be best to consider the possibility beforehand that this may take place, and then there will be no look of shock or disappointment on that beautiful bridal face.
This applies to everything. Road trips, job interviews, parties and relationships. No matter how much you plan, you can't always win.
To change your view on how things run, you need to realise that you have no control over people, time, traffic or even the sun. It would be wise to allow life to teach what it wants you to learn. Make your plans, but expect twists and turns.
If everything just went as you had planned for it to, then you would only experience life from your view. How nice it is sometimes to see that there are other ways in which we can be.
Remember that 50 percent of pregnancies are apparently unplanned, and if this was not the case - perhaps you and I wouldn't even be walking this land.
Make your plans, but just be aware that your plans have plans of their own and may take you anywhere.