Losing weight...???

Ashley • 40, TTC #2...22 years later...lol
Is it common to lose weight in the first few weeks of pregnancy? We're ttc #2 and I'm showing quite a few symptoms but I don't quite know if it's just my mind or reality. I've lost 10 lbs since 10/3 yet my pants are fitting tighter...I had baby #1 16 years ago so I don't really remember how it feels to be pregnant...any advise would be helpful.