When should I start using a portable breast pump?

Generally, if you plan to return to work after maternity leave or have travel arrangements, starting to use and familiarize yourself with a portable breast pump a few weeks before these plans is a good idea. This gives you ample time to adapt. 

Additionally, if you feel your milk supply is slightly low and you want to increase pumping frequency to boost it, or simply desire more convenience and flexibility in your daily pumping routine, a portable breast pump can be very helpful. 

Most importantly, listen to your body's needs and consider your baby's situation to decide when and how to best use it.