Before planning to start a family, look at the nature of jobs both you and our partner are currently involved in. If either of you works with chemicals, lead, anaesthetics or X-rays, it may reduce your chances of conception. Also, once pregnant, your baby will be at risk. If you have any concerns regarding the nature of your job, you may want to discuss this with your doctor first. There is not much point in discussing with your employer till the time you are actually pregnant.
In the meantime, you can try and move to a safer job or at least try and minimise the exposure to risk factors. Once your pregnancy is confirmed, you can bring this up with your employer who is then bound by law to move you to a safer job. If no such alternative is available, you can be dismissed but your maternity rights and benefits will not be affected.
Contrary to popular belief, working with computers is not harmful to your unborn baby.