Look for a prenatal class specifically they will have more knowledge as to what is safe and beneficial during pregnancy. The hospital I am delivering at has a new parent resource center and my yoga class is taught by a labor and delivery nurse who is also a yogi. She is amazing. I think yoga is amazing and anyone could benefit from it. We have girls ranging from 16-39 weeks in class. Good luck!
Should have been I started at the beginning of my second trimester.
I am doing prenatal yoga now and love it. I at the beginning of my second trimester. A big part is finding the right instructor. I have been to two different ones and one was very concerned with how my pregnancy was so far and any previous injuries. I have had some problems with loose joints and she paid close attention to make sure I was doing poses right. The other instructor didn't talk to me at all and I wasn't as comfortable with her. I would double check with dr but I think it's worth your time just take it easy and listen to your body. If it helps I have very little history doing yoga before this pregnancy. Did it a few times like 3 years ago but that's it.
I would be very iffy about it. Especially during the third trimester and youre just starting it. I think the safest excercise is swimming. No gravity pulling and its an exercise that uses all your muscles. The no gravity part is the best part of it though. You can just paddle lethargically in the water and it'll loosen you up a bit.