I'm 13 week and 1 day

Tia

How many week/Months do you think is good time for you to start buying diapers?!

I really trying to be in stock like this before my baby comes! I don't want to have to go to the store to buy anything for atleast 6Months. I Even Been Trying To Learn To Coupon So I Can Get Them Cheaper! So when Do You Guys Think It's A Good Time To Started!