Bumping transmission

After changing the transmision fluid in my 2002 rx 300, when it shifts it bumps before changing, could i have done something to the transmission with changing of fluid???

This is just a guess 'cause I don’t know the intricacies of the Lexus transmissions. Most transmissions have an EPC (electronic pressure control) relay to regulate the transmission fluid pressure. Sounds like your relay may be disconnected, if so your transmission fluid is operating at the wrong pressure.

Are you sure that you used the correct fluid type?
Using the wrong fluid can cause symptoms such as you describe.
I believe that this transmission calls for T-IV fluid.

Has the transmission fluid been changed on schedule or is this an overdue service?