Losing weight while Pregnant

Hello! I am about 7 weeks, and 4 days along and while I've had pretty bad morning sickness I've actually lost 5 pounds since I found out I was pregnant a little over a week ago. I am a bigger girl, proportionate but bigger. I began my pregnancy around 267, which was a pretty normal weight for me until then. I weighed myself today and am 262 exactly. I've heard that some bigger women can actually lose weight, and everyone is different but my best friend is the same size as me (granted she's 8 months along) but she was told she should only gain maybe 10 lb, and has gained like 40. So is this normal or should I worry? I eat as much as my body will tolerate right now to keep things down!