1st trimester shouldn't really require any extra calories, but you should try to be aware of your overall nutrition.

2nd trimester they say you'll need about 300 extra per day; 3rd trimester 500 extra.

Unless your doctor says differently, you're carrying multiples, etc.

alrighty

And not just the first trimester. It's 300 extra a day for your whole pregnancy if your of average weight when you got pregnant. If your considered underweight, they recommend more, and overweight less

They say only 300 more than your usual intake.