I had three babies while significantly overweight (100+ lbs) and the pregnancies were perfectly normal and healthy. I never got GD and had no other complications. I chose to have midwives for my pregnancies because many OBs are very fat phobic and not very knowledgeable about larger women and normal birth (or normal/natural birth at all.) If I were you I would research the midwifery model of pregnancy care (look for a book by Sheila Kitzinger or Henci Goer) and start charting my menstrual cycles to learn about your body.
You may be overweight (or obese) but that doesn't mean that your body isn't just as capable at producing a healthy baby. BTW, my oldest sister is also obese and has had 7 children with no complications.
Best wishes for a great marriage and a healthy future pregnancy!