Someone recently inquired about yoga if they were new to yoga, not exactly active and, almost five months pregnant.  Yes, it is absolutely a great idea.
Unlike some yoga teachers, as a yoga therapist I am not in agreement that "any yoga is good yoga" for "everyone" or "every body". When pregnant, and if new to activities, you need to take your time and ease into it.
Yoga is fantastic as you can customize not contort (my mantra with my philosophy on yoga). 

However, I don't agree that diving into a Power yoga class is the most efficient way to guide your pregnant or recently-given birth body into wellness.
Slow and steady is the way to go.
Build muscle and flexibility slowly, with intention, listening to your body.
First, you may have varied feelings and symptoms during pregnancy. One moment you may feel wonderful, another you may feel tired...the same way a new mother feels!
Our prenatal class is designed for the soon to be and new mother, taking into consideration her physical, emotional and mental demands. 

However, you may also take any gentle, basics or renew class as well. If you've already given birth and have the green light to resume activity from your medical professional, then you can feel comfortable also with Peaceful Power classes; and realize some people prefer Peaceful Power while others prefer Power. I state Peaceful Power as I do feel that a new mother needs to think a bit more about herself, and raise her energy while also decreasing stress more than a typical power allows, so that is my logic for suggesting the Peaceful Power class.

Overall, again, listen to your body, let your teacher know you are pregnant or are in the first three months after giving birth, or are having concerns about which class to explore or start with.

...and congrats on your bundle(s) of joy!