There are also apps to track how much weight you've gained, how often your baby kicks and eventually how far apart your contractions are. There are even smartphone-enabled devices that let you listen to your baby's heartbeat at home.
Like a lot of second-time moms, I didn't feel the need to gorge myself on pregnancy information this time around. But I did download some of the more popular apps. I stuck largely to free apps, though I also tested a $129 fetal heart monitor that attaches to a smartphone.
Although the apps don't cover everything an expectant mom needs to know, they offer enough that I've barely dusted off my pregnancy books this time around.
BabyBump (free, or $4 for ad-free version with additional features; for Apple and Android devices) • Like the other pregnancy apps I tried, you start by entering your due date, weight and other information. The app creates a chart tracking your progress and showing the number of days left.
BabyBump also encourages you to upload a photo of your expanding belly each week to create a time-lapsed series of your growth, but I didn't bother with that.
There are daily tips and a weekly update explaining what's going on with your body and baby. You can play slideshows of you and your baby's week-by-week development. These are in the form of drawings showing an expanding belly and what's inside.
You can also join online pregnancy groups and use the app to keep a journal.
The free version has advertising on the bottom. The $4 pro version doesn't. The pro version also has a kick counter and contraction tracker, along with planning tools for shopping, name selection and birth announcements. I didn't feel the need to pay.
WebMD Pregnancy (free, for Apple devices only) • I like this app the most. Like the BabyBump app, there's a pregnancy calendar and weekly illustrations showing development. But WebMD's pictures are more vibrant and less cartoonish, though a bit more graphic.
There are daily tips and suggested questions to ask your doctor at your next appointment.
You can keep track of your doctor's appointments and log your weight and blood pressure. Although I used the app to track how much weight I was gaining, I didn't bother with the blood pressure and found my Google calendar to be more useful in logging appointments.
The app includes a kick counter and contraction timer for free, whereas I had to pay for those features with BabyBump.
I found this app easier and more fun to use than BabyBump.
Bellabeat (free app, but heart monitor costs $129; app for Apple and Android devices) • At-home fetal heart listening systems aren't new. There are a handful of products of varying prices and quality, but many people have complained that they don't work well and aren't easy to use, especially in the early stages of pregnancy.
You plug the Bellabeat heart monitor into your smartphone's headphone port, and then plug a set of earbuds into the device. It runs on two AAA batteries.
The companion smartphone app detects the baby's heart rate and lets you record the sound. You can even share the audio clip through Facebook, Twitter or email.
Like the devices used by doctors, the Bellabeat uses high-frequency sound waves to pick up the heartbeat. But this isn't nearly as advanced as the one at my doctor's office.
I had a mixed experience with it.
The first time I tried the Bellabeat, I was 37-weeks pregnant and pretty huge. I managed to pick up my baby's heartbeat after a few tries. But a few days later, after the baby had moved into a new position, I couldn't seem to find it at all. I just got a lot of whooshing noises from the device.
Eventually, I picked up a faint heartbeat. I wasn't worried, but I can see why some doctors don't like these gadgets. They can cause unnecessary distress.