You can do whatever you want... but i had a c cup when i had my one side masectomy ,bigger now 18 years later , so i find it very comfortable to wear a prosthesis every day, once i got some good pocketed bras and prostheis combos that worked for me. Well worth a visit to a fiitter for an intial consult and guidance ,or an online appointment if your rural and none nearby .Its not just the prostehsis , its the bra and how they work together. Then re build up a wardrobe of different bras, sporty, lacy, soft , smooth cup, etc
Much easier for smaller breasts . No we don't have official 'uniboob' bras in Australia, but I have seen people sew them, and it is important to support your remaining breast .If you find your comfortable going asymetical sometimes, there are proably some sport crop ones that may work .Check out 'Know your knockers.'
But plenty of types of prosthesis, different weights , but only from speciality lingerie stores that you have to track down. I can't attache pdf here, but I have put images of the lists i made for sutherland breast cancer support group on the the Facebook page Flat Life Australia ,it include online store options. Make sure you join there if you use FB.
Good store front one at Figree/Woolongong. CasaMia
Its nice to have a foam one for at home, silicone is much more relaistic weight and texture and drape - when someone hugs you it is like flesh.
ther are swim ones that drape differently again so when lie down they fall different and great if do a lot of swiming as more robust plastic.
There is also 'Boost' style for time when want a light weight fun shape.
( that is unique , not in shops . only https://www.thepositivehealthproject.com.au/boost)
Too light a breast form and the cup and band on that side may ride up as you move around.
It will feel weird, but you get used to wearing a prosthesis , all part of accepting new body and healing emotionally .
Also good it was one surgery, not mutiple and complications like others seem to have. There are a lot of benefits to retaining one healthy breast.
I have heard the Hugger luma is a good sporty bra in the prarie range. I have only tried the Vida. Prima is for post surgery or if have any chest torso swelling.
https://lymphshop.com.au/compression-garments/bras/