I love animals and have always had cats.
Within a month of buying our house together, we adopted two cats.
I also take in sad, stray kittens and nurse them to health and adopt them out once they're ready.
Last summer I ended up with a litter of 5 tiny 3 week old kittens. I had been getting the baby "itch" at that time but those little guys consumed my every moment. I was basically their mother for a month or so. I had to feed them every 4 hours, stimulate them to poop/pee for the first few days, too. One of them ended up staying with us (see my sig). I'm such a cat lady.
If you wanted a dog before, I would say get one. If it's just something to preoccupy you until you have a "real" baby to take care of, I would not. A dog is a commitment for the rest of it's life and if you don't think you will love it and pay as much attention to it once a baby comes, it might not be right for you.
I'm a cat person because IMO they are less maintenance. Just leave out clean litter, food and water and they're all set. You can even leave for a night or two and they'll be fine. Not so much for a dog.