Weight lifting is not really a problem - especially 10 lb. weights, babies weigh more than that and you'll be doing a lot of lifting then!!!
The only thing to be careful with in weight lifting is lifting that requires a real Valsalva - you know, increasing abdominal pressure, like you would if you were lifting a huge barbell or having a big BM - and even that's not really an issue until the third trimester. So go ahead and do your squats, arm exercises, even crunches. Just avoid getting way overheated in the first trimester (no jacuzzis!). I lifted weights all through my second pregnancy.
