Breastfeeding Management for the Clinician: Using the Evidence
According to this link 6 to 12 months healing are for a nipple piercing, but some can take as long as 18 months.
Definitely avoid it.
Chlorine and the bacteria in unchlorinated waters may both irritate
your newly pierced ears. It is therefore recommended that you wait 2-3
weeks after your piercing.
And while that is about ear piercings, nipple and ear piercings both break skin integrity and so present the to risk of infection.
According Nhs.UK any water including lakes and hot tubs can cause harm. Harm including massive life threatening infections that can lead to death or disability. And states:
You should avoid swimming for at least 24 hours after having a
piercing, and ideally until it has healed properly. While it's still
healing, it's important to keep the piercing dry as there's a risk of
While, nipple healing times are defintely not the same as ear or tongue piercings probably I would consult on that and possible bandages to wear if you decide to swim during the healing time. But you should seek the council of a professional and for go swimming, it is better to be safe than sorry.