Is losing weight in the first trimester safe?

I was doing Keto for about 2 1/2 weeks and lost about 10 pounds. I fell off my diet slightly for about week and found out I was pregnant.

My question is, I felt a lot better, less bloated and hungry when I was eating that way. (Low carb- 20 or less per day- higher fats, and between 1000-1200 calories per day.)

Is this way of eating safe for the first trimester? I’m already considered obese for my height (5’2 and 180 lbs) and I don’t want to gain a ton during pregnancy.

Thoughts??