Overweight and pregnant

Rebecca • Married to my high school sweetheart. Currently have 2 children Xavier Cole and Mariah Nicole.
So I have been trying to lose weight for almost a year and nothing works. I did cardio workouts, I ran the track everyday, and watched my calories and an sugars. Nothing worked. I went to the dr and all she would say is watch what you eat. An I told her I do and that's all she kept saying. Now I'm pregnant and according to my bmi I'm obese. I also have preeclampsia and being obese can trigger it again. So I'm still wanna lose weight but I don't know if I should since I'm pregnant. What's your thoughts?