The swelling can be usually associated with venous blood collection at the site of venepuncture..
If the size is increasing over the days, there is a possibility of local Hematoma or some soft tissue swelling.
Next Steps
If it is causing issues, better to get an ultrasound of the wrist to rule out any other cause.. You can apply crepe bandage over wrist for compression..
Health Tips
Avoid heavy weight lifting.