I've been sedentary for several months, but my doctor still suggested that I attend a prenatal strength and yoga class. It was one she had attended herself and was familiar with, and she knows I'm not active. The first class was last night, and it was very tough for me. I'm 13 weeks pregnant. The class was an hour long with 40 minutes of strength exercises (squats, lunges, pushups, etc.) and 20 minutes of moderate yoga. At one point near the beginning, I felt like I was very out of breath. I was expecting to feel faint or break into a cold sweat, so I lessened my intensity but kept going for the rest of the class. By the end, my legs were shaking from muscle fatigue. Everything I've read says that pregnant women should not start out doing exercise that is way more intense than they are used to, and I'm worried that I've caused oxygen deprivation to the baby. Worst fear, of course, is that I hurt or killed it. My breathing felt somewhat okay after the class, but when I went to bed my heart was pounding and I had a hard time sleeping. Can't tell if it's due to the exercise or anxiety or a combination of both. Heart still seems to pound heavy today when I'm up and moving, but it's okay at rest. Just heard the baby's heartbeat last week. As far as I know my blood pressure has been okay, or the doctor hasn't told me otherwise. I want to continue exercising if everything is okay, but I wonder if it's better to start out slower than what my doctor is suggesting. Thanks for your help.