I think as long as the exercise is not strenuous..and you're not over doing it you will be just fine. The best ive heard is walking, I used an elliptical routinely before I got pregnant, I dont anymore because ive just not had the energy ( I also have 2 boys that are 4 and 2) and I work as a server in a restaurant 6 days a week. So I feel like with working and taking care of my boys I get enough in. Just no lifting!
I walk almost everyday. My OBGYN actually encouraged exercise, however be safe and listen to your body. Since you had a routine prior to pregnancy your body is use to it somewhat.
I'm preggo with twins and my doc said walking, yoga and swimming were the best but no bouncing or high impact exercises.