Dear Christina, I recently found out that I am pregnant. Yea! I am due in late January and am beginning to think about what maternity clothes will be necessary... and which brands have fashionable, yet affordable, maternity lines. Let's face it, there's a lot of maternity clothes out there that are NOT cute... and I don't think I can afford to stock my closet with Isabella Oliver maternity wear (love it!). Do you have any advice on what essential items of clothing I will need as I grow and move through summer to fall to winter... in Michigan? I've heard wonders about the Bella Band from Ingrid and Isabel... and I'd love to be able to wear my pre-pregnancy jeans, pants, skirts, etc. as long as possible. Any experience with this product? You seem to be a fan of The Gap and Old Navy Maternity lines... any others?
Stacie
Answer:
Congratulations! Oh the memories. You'll soon be in the "I don't look pregnant yet, just fat, stage" because until your bump really starts showing, it will just feel like you can't fit into anything.
You know, this is actually a really good time to be pregnant, because the baby doll, empire and longer tunic tops are still selling in stores and you can get away with these "regular" clothes for awhile!
Also there's lots of pants being sold now with knit waist lines (like the ones pictured below from Motto on QVC)- I am wearing some short right now that I bought from Target with that kind of waistline and drawstring-super comfy! I can see how a pregnant woment could get aways with wearing them for a few months.

If I were you, I would not invest in any pricey pieces b/c it is such a short time in your life (unless you just want to get the esentials from Isabella Oliver).
When I was pregnant, I bought alot from Liz Lange at Target and yes,
Old Navy (image below), and some Gap-but also some Motherhood Maternity-whatever seeemed to have cute, practical, affordable and trendier clothes. Clothes that made me feel comfortable and fashionable at the same time- a big bill to fill!
I have heard wonders about the Bella Band too (or others like it). BUT, it will depends on how comfortable you are as a pregnant women. Here's what I mean: that kind of band really irritated me as I got further along in my pregnancy b/c my pants would slide down and I'd always be hiking them up (now other pregnant women I talked to- not a problem). So towards the end, I would search out the kind of pants that just covered my entire stomach- ahhhh, the relief- BUT it depends again on preference.
SO, Here are some suggestions for basics: black jersey knit pants, skirt and dresses; some jeans you love and feel stylish in (you'll probably be in them most of all), same with khakis or cotton stretchy pants. Maternity stretchy camis, tees and long sleeve tops with get you through the winter (wear the long sleeve under the short sleeves you wore in the summer and early fall-like in the picture, below).
Banded bottom(below), tunic, and babydoll tops will be your new best friends, along with leggings, I suspect (picture from Motherhood Maternity)! 
A good resource to check out would be Allie at the the blog
My Wardrobe Today because she was just pregnant this past year and showed all of her maternity outfits and where she bought them(check her back posts).
Hope that helps! "Part two" of your question will be posted tomorrow!