changing your diet after conceiving

any advice on how to easily transition my diet after getting pregnant? i've been on a low carb/low calorie diet for last year to help getting pregnant, and am now worried about trying to add back carbs. I felt better going low carb and now when I eat bread I feel sick. not sure what amount I need to be eating for little one, but just the thought of adding 500+ calories back into my diet and 100ish carbs makes me think I'm gonna gain so much weight, which I know can be bad. I'm still early preg( 5 weeks). any advice?