I and all the other women in my family lose weight the first trimester. Even the skinny one.
I lost 30 pounds 1st tri with my first as a result of hyperemesis combined with starting out 100 pounds overweight...I finished it 10lbs down from my prepregnancy weight. I lost 10 lbs 1st tri with my second daughter, and finished up 16 pounds over my prepregnancy weight. I tend to say I gained 26 pounds with her, but oddly I always say I wound up 10 lbs down with the first.
I don't really think it matters how you call it. It all depends on the tone of the conversation/thread it comes up in. If someone's boasting about how little weight she gained, I'll trot out the "10 lbs down" thing from first pregnancy. If it's a complaint about how little weight their dr wants them to gain, I'll mention the 26 pounds "overall" I gained with my second.
I'm odd that way.
This time around, I lost 6 pounds the first trimester, & now at 22 weeks 2 days am at the same weight I was when I got pregnant. Depending on my mood, I'll either say I gained six pounds or I haven't gained any over my prepregnancy weight. Either is true.