Yes, you can always adjust top, middle and base notes. As well as before adding a carrier, and afterwards. It's always best to let it sit another few days before judging the impact of your modification(s). It could also be a good idea to make small adjustments with parts of your original mixture to learn from the differences and impact, by comparing them afterwards.
See also my blog for formula's and tips: perfume.sparla.com
Have fun, happy perfuming,