I was 97kg when i fell PG, 95kg at 11 weeks (lost a few with morning sickness) and 101kg the day she was born. I didn't diet at all, my body just didn't gain extra weight i didn't need. I put on ALL of my weight AFTER 36 weeks too, i have my pregnancy notes and i see my 36weeks appointment says i was 95.4kg...

DD was 7lbs 14.5oz, 3.58kg. I was back to 95kg on day 4 (which was the first time i weighed myself after the birth) and lost a subsequent 18kg, taking me down to a healthy (for my height) 77kg, through breastfeeding and exercise.

As others have said, as long as you're not dieting, not dangerously underweight and feel fine then you've nothing to worry about.