Weight loss

I was just hoping for some feedback. I just weighed myself this morning and I have lost weight since I had my physical which is when I got the official notice that I am pregnant. I am 7 weeks 3 days and have not really had many symptoms other than sore breasts and occasional cramping which I have been told is normal. No spotting or anything. I wish I could contibute it to nausea and vomiting. The only thing I can think of is that I started eating healthier once I found out I was pregnant. Has anyone else had this happen or know if this is normal?