Thanks for your query.
I understand your concern for new family member.
I suggest you to give EXCLUSIVE BREAST FEEDING till 6 months of age.
Do not worry about your milk production.Take plenty of fluids and good nutritious diet .Sucking stimulates milk production,more your baby sucks more will be the production of milk.Be stress
Regarding increased urination it is normal.Do not worry about it.
BREAST MILK IS A BOON FOR BABY/