Anyone Having Quick Weight Gain?!?!?!

So, this is my fourth pregnancy and my weight gain this time around has been more accelerated than any of my previous ones! I always gain more than the "recommended" amount, but I also have near 10lb kids. I just don't usually see the weight pile on until 7 mnths or so. I had a 2nd trimester loss in March, but I had still only gained 10lbs. I feel like many of my choices nutrition wise haven't been very different from previous pregnancies and in many ways have been better! I also hit the gym(including weights) several times a week, especially as the nausea lessens.

I just weighed myself and am up 18lbs at 16wks?!?! Other than my boobs and belly and a bit in my legs, I'm not even that big!!! Please tell me there is another momma out there wondering wth!!!