36 weeks and feeling sick. Nausea late in pregnancy?

I am on preg #3 and have never had any morning sickness worth talking about (maybe a touch in the afternoon for a couple of weeks at the beginning~ ginger ale and crackers would take care of it). Now, I'm 36 weeks and having been feeling nauseous quite often. Usually when I wake up from sleeping (whether it's in the am, or after an afternoon or evening nap). I also find it bothering me if I've just eaten or if I'm hungry. I'm just wondering if this is a sign of anything serious, or labour approaching?