had a steady gain and now am losing weight at 26 weeks

Is this normal? There's no reason for me to be losing weight now. I have the same lifestyle of running around after kids and eating semi healthy( semi easy(sandwiches and leftover spaghetti) type foods. It's all pretty much exactly what I have been doing. I actually have gotten a sweet tooth lately and will find myself indulging like once every couple days. I lost ten pounds in the beginning but slowly gained it and then six pounds. It was about a pound a week since week ten and now I've lost that six pounds in about a week. I feel fine and baby had been active. I felt her less yesterday but with helping out with kids programs I don't think I would have felt her with all the motion anyways. Is this normal for anyone? I'm beyond grateful to be at my original weight at 26 weeks but I still want to be sure baby is growing fine.