You should first check with your doctor. If allowed then you can continue most exercises that you have already been doing as long as they are not jarring movements or have a risk of abdominal injury. Else it's best to just start with a walking program. It is also advisable to sign up for a prenatal exercise class as you can work out under supervision. There are many options available on Babychakra and you can choose one close to your home.

walk.. but not brisk walk, first and last trimesters are very risky so plz b careful