Anyone not gaining weight yet?

Caitlin

I’m 16 weeks pregnant and I’m 1000% showing (none of clothes fit either) but I haven’t gained any weight. In fact I’ve lost 2lbs. Is that weird? Is anyone else like this? Should I be worried? I keep reading I should have gained 5to 10lbs by now. I’m not dieting or exercising except just light walking a few times a week.