Is the swelling in my feet normal?

So I'm 36 weeks and noticed last night when I was going to bed that my feet were swollen. Woke up and they were still swollen. I work at an apartment complex as a leasing consultant so I'm up and down on my feet all day. Got off of work this evening and my feet are definitely have ballooned out. Before last night I hadn't had any swelling in my feet at all, just a little in my hands where I haven't been able to wear my rings in almost a month. Tuesday when I went in to see the doctor for a non stress test I had gained 5 lbs in 8 days which I've never gained over 2 in a week before. I'm only asking because my mom is being kind of spastic about the whole thing and wanting me to call the on call nurse. Figured I'd ask here 1st and see if this just sounds like normal swelling or if I should be concerned about preclampsia and call my doctor. Thanks!