How to prevent a fallopian tube conception
There is nothing you can do to control where a fertilized egg implants. You can not prevent it from implanting in the fallopian tube.
The best thing you can do is see your doctor before you start trying to conceive to get a check up and make sure you are healthy. If you have any concerns about abnormal menstrual symptoms make sure you tell your doctor. Start trying to get pregnant after you get the all clear from your doctor.