You're supposed to eat 2,300 calories when preg but obv in first trimester it's a struggle
What a load of nonsense. A person's calorie intake during pregnancy is totally dependent on their HEIGHT and their weight at the very beginning of the pregnancy.
You don't need extra calories during the first two trimester's unless you are woefully underweight. In fact, if anything people should probably be reducing their calories due to lower activity levels since most people feel too shit to do much other than vom and sleep. In the third trimester women need an additional 200-300 calories a day. That's it.
Of course, many people eat much more because hormones drives them crazy hungry, and that's understandable, but it isn't a medical REQUIREMENT.
2000 calories is the average calorie intake requirement for women. An average is just that - you can't take an average and apply it to a specific woman. That would be like saying "The average shoe size in the UK is a size 6, so you must wear size 6 shoes, regardless of whether or not they are like boats on your feet.
If someone is telling you that ALL women need to be eating this SPECIFIC quantity of calories a day, from the very beginning of pregnancy, then they are either morons, you misunderstood, or they were drunk.