It's absolutely OK! This is a very personal choice and no one should tell you that it's wrong. There are many lactating women who do not want to put the baby to the breast, yet they still want to provide breast milk for their baby. This is where the age-old "process versus product" debate begins...Is it the act of breastfeeding or the nutrition (or both?) that is best for the baby? Once again, this a very personal decision and there is no right or wrong answer. Some moms are very modest or uncomfortable with the idea that the baby would be at the breast and that's OK.
The bigger concern is maintaining a strong milk supply. Using a hospital-grade breast pump is key. It will mimic your baby's suckling patterns and stimulate your milk supply while extracting the maximum amount of milk possible. In order to obtain enough milk to sustain your baby, it is necessary to pump every 2 to 3 hours during the day, which is essentially how often the baby would be feeding. However, because the breast pump does not compress the milk ducts exactly like the baby, you should be mindful of how your supply is doing. Make sure to drink plenty of water and eat well, and as crazy as it may sound at this stage, try to get some rest! This will allow for a healthy milk supply.
Many moms who have been pumping since Day One have a very easy transition going back to work because there isn't any stress of introducing a bottle and teaching your body to accept a pumping schedule. However, if you find that your supply is dropping a bit from regular ol' work stress, don't worry! There are many ways to increase your milk supply.