Cyst on Neon Belly

[Camescu]

I noticed today that one of my neon tetras has a really fat belly. I'm
A bit of a novice so thinking it could be one of a few things.

Just stuffed itself silly on love bloodworms?

Some Sort of cyst?

Carrying eggs?

The photo isn't the best quality. Any input would be great fully received.

It isn't losing colour and still schools. No white tail spots. Just a really fat belly

 

[Camescu]

Parameters are good

Ammo and Nitrite 0
Nitrate 10-20
Ph 7.6

All other neons are fine.

 

[Mattyfelts]

Parameters are good

Ammo and Nitrite 0
Nitrate 10-20
Ph 7.6

All other neons are fine.

Do some water changes and get the trate down but im not sure what it could be.