EXCESSIVE POSTPARTUM WEIGHT LOSS

I have so many people compliment me on my weight loss post baby; I gained 33lbs and have lost 50lbs. I'm starting to get worried something might be wrong. I haven't worked out and haven't changed my eating habits. I'm 5'10" and now weigh 150lbs. I also exclusively breastfeed. Anyone have this experience or know what could be causing it? I'm going to the dr this week, but wanted your input because I'm anxious about it.