All insurance plans must cover a breast pump (https://www.healthcare.gov/coverage/breast-feeding-benefits/). Talk to your OB and they should have the paperwork for you to complete. It was a pretty easy process!
I've been reading Making More Milk, it has a chapter on confirming your baby is getting enough milk (wet diapers, baby's weight, and a few other tests i can't remember off the top of my head) and best ways to supplement without compromising your supply such as using a supplemental nursing system instead of a bottle like this: https://www.amazon.com/Medela-009-0003-Supplemental-Nursing-System/dp/B000W73YKY
I don't have the book with me right now, but check out the kindle version as it may be helpful to you! https://www.amazon.com/Breastfeeding-Mothers-Guide-Making-More/dp/007159857X
I was lucky and a friend gave me a bunch of stuff. I didn't feel comfortable in a lot of her shirts though. I ended up buying 3 t shirts that have elastic in the sides. I'm 34 weeks currently. (5'4, about 148 lbs, 36 D before pregnancy) . I've found that these kind of shirts stretch well and have looked the most "normal" and flattering during my pregnancy. Here's a link to an example of the kind of shirt. https://www.amazon.com/Happy-Womens-T-shirt-Maternity-Sleeve/dp/B01GK1M3RU/ref=sr_1_23?s=apparel&ie=UTF8&qid=1488333926&sr=1-23&nodeID=7147440011&keywords=maternity+shirt You can find versions of them at most stores that sell maternity clothes though. Most of the other shirts and sweaters I got look like tents on me now.
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