Weight loss (calorie counting) and pregnancy

[Times10]

My BMI is 26.3, and according to the TDEE calculator, I need 1780 calories to maintain my weight.
I’ve been losing weight steadily, by sticking to about 1500 calories, but am now 5 weeks pregnant.
Is it safe for the baby if I cut down on calories (from my TDEE) a little in the first trimester? Or should I not eat my exercise calories instead? I don’t want to harm the baby, but would like to tone up if possible (and hopefully lose a little weight, but only if it’s safe)