A.P.
I see you're 18 - and about 5/6 months along?
There's nothing stopping you from doing anything you want - within reason. Don't go on roller coasters, obviously. :) And nothing that will make your stomach bounce too much.
Head to the library - check out the section for parenting. TONS of great reading - here's my recommendations : anything by Ferber, the On Becoming Babywise series, the Baby Whisperer.
I'd stay away from the encyclopedia looking ones. They list everything that could possibly go wrong, and have one paragraph that says "oh, that only happens to .0001% of children".
Go for more walks! You have to be healthy for two and fresh air is good for your body, sunshine has Vitamin D (studies show leads to healthier babies), and the exercise will make you feel better mentally and physically!
Learn to cook. You've got 10 years of eating at home in front of you. At least. Might as well make them taste good!
Find your pediatrician.
Do all the things you did before you got pregnant (except for the bouncy things! :) )