This is my first pregnancy and I still do the things I did before. I'll go grocery shopping and instead of making multiple trips to the car, I'll pile all the sacks on my arms and carry them in at one time. A lot of the time I am pretty weighed down and by the time I put all of the sacks down, my arms are burning like I just did a work out, lol!!! I was moving a light night stand the other day and my hubby yelled and said, "you better not be lifting that". I know I need to be careful, but I'm pregnant not incapable. I know my limitations and I would never do anything to jepordize the baby.
I say, if your body is used to it, then it should be okay, just know your limitations and don't over do anything. If you are going too far, your body will let you know (or baby will).