If you are thinking of (or trying to) get pregnant, it is best to join a class as soon as possible, before you become pregnant, so that the teacher can get to know you and you can improve your overall health before conception. Otherwise, you are limited to classes taught by senior teachers (which can be hard to find). I am now qualified to Junior Intermediate 2 level, which means I can teach ante natal yoga, providing there are no complications in the pregnancy.
Please get in touch if you would like to discuss this with me in confidence. Please tell your teacher if you are pregnant and they can advise you how to practice yoga safely.