Thrift shops are great, if you have any friends of family that has had a child recently they proobley have some old maternity clothes laying around also. I also see people posting ads on craigslist all the time asking for free maternity clothes to be donated to them. Ive seen a few of your questions and money seems to be a big concern with this pregnancy. Are you in the US? If you havent already, sign up for medicaid, its completely free medical insurance for pregnant women. You should also sign up for WIC for you and the new baby, WIC is like a small version of food stamps for pregnant women and children, every week you will have vouchers for foods that you can get for free to make sure you are eating properly, some of the things included now are milk, juice, cereal, panut butter, veggies, fruit, and alot more. It really helps.
You wont need them until your 6 moths pregant as most of your own clothes will accomodate. Whenyou start getting big, your partners clothes will suddenly have a new use. And you can get away with having 2 big or maternity items to get you through when your out in public. Larger sized womens dresses can double as maternity gear.
There are many online maternity stores which focuses on good quality in affordable rates. A reputed online store like Fertile Mind is good in terms of selling out high quality maternity dresses and other things in a suitable range.
There are bound to be heaps of cheap, good quality maternity clothes at second hand shops. If you are low on cash see if you can grab a cheap stroller/pram and bassinet while you are there.
Any local thrift shop, or yard/garage sales usually have cheap maternity clothes, as wells as cribs, strollers, baby clothes, baby toys, etc...
Please tell me you're not pregnant. Are you still living with your grandmother or whoever?
Check out your local thrift shops for good buys.