I would say no for 2 reasons – Retainers are for short period wear not long period as the plastic can break down over time and well it would be breaking down inside a fresh piercing BUT the other major reason is that for the 1st 2 weeks your tongue must have in it a long bar as your tongue will swell and be uncomfortable – you cant talk all that well for at least the 1st day after that you start to get used to it but eating on the other hand can be tricky for up to the first 2 weeks until you go back to the piercer to downsize your bar – but you will accidentally bite it at times (yes that hurts) but being plastic you could break it when you bite it and then it falls out and you have to have it pierced again (thats of course if you can find a retainer the right length – but I doubt any piercer will pierce you and put in a retainer – if your already pierced its a completely bad idea to change it already – you will probably find it already starts healing in the time of removing the jewellery and putting in the retainer.
I would say no for 2 reasons – Retainers are for short period wear not long period as the plastic can break down over time and well it would be breaking down inside a fresh piercing BUT the other major reason is that for the 1st 2 weeks your tongue must have in it a long bar as your tongue will swell and be uncomfortable – you cant talk all that well for at least the 1st day after that you start to get used to it but eating on the other hand can be tricky for up to the first 2 weeks until you go back to the piercer to downsize your bar – but you will accidentally bite it at times (yes that hurts) but being plastic you could break it when you bite it and then it falls out and you have to have it pierced again (thats of course if you can find a retainer the right length – but I doubt any piercer will pierce you and put in a retainer – if your already pierced its a completely bad idea to change it already – you will probably find it already starts healing in the time of removing the jewellery and putting in the retainer.