Some yoga beginners have told me that they are stopping their practice of yoga since they are trying to conceived. I was surprised. This is because most people actually practice yoga to assist with conception and delivery of the baby. In other words, it is safe to practice yoga even if you are trying to conceive as long as you are guided by a qualified yoga instructor. Just remember to take it easy and pace yourself to avoid injuried.
In general, exercise benefits the entire body and it helps if you are trying to conceive. Amongst the exercises, yoga is one of the low-impact exercise to tone and tighten the muscles of the body. Also, it is easier to start practicing yoga before pregnancy so that you can make it a habit. It is much easier to develop it as a habit when you are not dealing with morning sickness and fatigue. Another benefit of yoga is that it reduces your risk of gestational diabetes and other pregnancy complications. Lastly, yoga helps you relax, which can make coception easier.
While there are many different kinds of yoga, I recommend starting with restorative yoga and deep breathing as they would aid in relaxation.