I have 2 dogs and a cat. I am the closest with my Yorkie, Bailey. She was my first dog, and we had her alone for 2 years and basically fell head over heels in love with each other. I've never been so darn close with any animal in my life. Sometimes I have to stop and remember, she's not human, shes just a dog!!!!!
Anyway. We've always been close, but since about 4 months into my pregnancy, Bailey has been staying by my side EVERYWHERE. I got laid off from my job at about 3 months, which was FINE because I want to take it easy. So I'm around the house until my partner gets home from work. This dog literally follows me from room to room, and even lays at my feet if I sit in the kitchen with company. She has NEVER laid at my feet when companies around. I can say this dog is constantly by my side now. Even when I lay down in bed for a few minutes to relieve some back aches, I will look down, and she's curled up between my legs. She even waits for me when I take a shower. She lie down in front of the door, and as soon as the water stops, she will start scratching at the door.
Websites claim they can't sense it, but I strongly believe this is the reason she's glued to me. Has anyone else noticed this change in their little companions?
I don't have experience with a dog doing this, but during my first pregnancy, our cats became VERY interested in me. None of them were lap cats, but all of a sudden all three of them were vying for attention, and a spot on my lap to sit.
So, yes, I do think that animals can sense pregnancy.
I am pretty sure my older dog, a hound, sensed both my pregnancies. Like the OP said about her dog, just spent much more time following me. She also knew she was looking for someone knew when we brought baby no 2 home. I came in without babe to greet the dogs since they had not seen me in a few days and were bound to be hyper. She sniffed me and looked around, looked out the window, obviously searching. I think it may be because dogs are pack animals who all care for the young. With wolves, only the dominant pair breeds and the others in the pack help take care of those babies. I figure we are her dominant pair.
I'm pretty sure we smell different to them, same as some people with cancers or epilepsy have physical changes that animals can detect in some fashion. At least I'm assuming it's smell, due to our hormones changing. At any rate, my dog is worthless but my cats are all insane now. Especially the dumbest one, he's totally super shadow cat and won't leave me alone!