This question is trying to understand if your advanced in your practice (and therefore your body is able to do a stronger practice), a beginner or somewhere in between.
As a guideline/benchmark to assist you with this response, it is recommended that pregnant women do up to 30 minutes moderate exercise a day.
Examples of conditions that require adjustment and special attention in yoga class include diastases recti, gestational diabetes, sacral or pelvic pain e.g. pubic symphysis dysfunction, high blood pressure, preeclampsia, carpel tunnel etc.