blocked tear duct??

Aly • Happily married. MC 4/2015👼🏻Baby girl 10/2016 💕 baby boy due 2/2018 💙
So I believe my daughter has a blocked tear duct in her eye. Just her right eye. Her eye has been slightly watery at times and pretty goopy- White to yellow discharge. It's only her one eye and it's not red or anything. Doesn't seem to bother her. I have read breastmilk helps but how do I get it in there? 😕How long do I let it go before seeing the dr?? Thanks!