Yes. We don't have scientific proof that pets sense their owners' pregnancies, but I've seen plenty of examples of this in my ten years as an animal trainer.

Your pets probably don't understand that in nine months a new baby will be joining your family, but dogs and cats do detect differences in your mood, posture, behavior, and body chemistry that clue them in to the enormous changes you're going through.

Your dog and cat will pick up other signs, too: They're masters at reading body language, so they'll notice when your movements start to get more awkward. Pets are also highly attuned to changes in your daily routine – say, if you're not taking your dog for runs as often as you used to, if you're spending more time on the couch, or if family members are treating you with extra care.

It's common for dogs to go on alert and become overprotective of their expecting owner from the very beginning of her pregnancy. I've worked with dogs that growled, barked, or blocked doors with their bodies to prevent other family members – even the baby's father – from coming into the same room as the mom-to-be.

Other dogs will treat their pregnant owner with more attention and care than usual. One woman I worked with had a difficult pregnancy and ended up on bedrest. Her dog refused to leave her side and had to be forcefully pushed outside to go to the bathroom. My own dogs waited patiently for me while I waddled through the park at a slower-than-normal pace.

Because they aren't as socially involved, cats are less likely to go through these sorts of behavioral changes. Three of my cats couldn't have cared less about my pregnancy. The fourth decided that my warm, vibrating belly was the best invention since cat food. I've heard other cat owners report a range of responses from uninterested to more loving and protective. But keep giving your cat attention and love during your pregnancy, as neglected cats may become more aggressive or act out by urinating where they're not supposed to, like in your bed or laundry basket.

To help prevent problem behaviors, try to stick to your pre-pregnancy routine as much as you can, and ask family members and friends to help when you're not up for a run in the park or a long brushing session. I advise clients to develop a plan for their pet while they're in the hospital, just like they'd develop a birth plan. Line up a caretaker for your pets and write down your pets' schedules for that person.

To help your dog understand that you still love him, be careful of the messages you send through your body language. Pregnant women often unconsciously place their hands over their stomachs, and dogs read this closed-arm posture as saying "I'm unavailable" or "step back." Open-armed postures, on the other hand, send dogs the message to "come here."

If your dog or cat starts seriously misbehaving during your pregnancy, or if you don't have experience preparing pets for a new baby, it's a good idea to get help from a professional trainer. Many offer "baby readiness" classes or individual training sessions to help pets adjust.

If you stay on top of any potential behavior problems, having pets during your pregnancy and afterward can be a wonderful thing for you and your baby. Studies have shown that spending time with a domesticated animal can improve mood, reduce depression, lower blood pressure, and even help you live longer. So enjoy!