Exercise and Weight

Christina
Before I became pregnant I was on a weight loss journey. When we found out, I had lost a total of 32lbs. I still have a ways to go, but since I found out I haven't worked out at all! I know that's horrible, but I don't want to gain all I have lost :( 
  I want to get back in it, but, I have some concerns. Can I lose weight if I'm obese and will the baby still be ok? And since I'm not at the level that I was before exercise wise, what would be the best way to start back up without harming the baby?
It's our first, and I have no clue. 
Plus, we were told it was going to be really hard for us to even have kids because I have fertility issues, and I don't want to risk anything....
Any ideas?