Priorities....... why can't I get them straight?

I keep thinking to myself that I NEED to exercise. I'm really don't want to gain 35 pounds like I did when I was pregnant with Madison. As of right now, 31 weeks I have gained 10 pounds which sounds really good. However I have looked at my chart from when I was pregnant with Madison. At 31 weeks I had only gained 14 pounds. BUT I gained 21 pounds in the last 10 weeks. (Maddie was born at 41 weeks.) I DO NOT, repeat DO NOT want to gain 20 pounds in the next 10 or less weeks. I would like to stick with a 15-20 pound weight gain. I'm trying not to worry about it too much but I am. I need to workout and stick with healthy eating and if I still end up gaining 35 pounds I will be fine. As long as I'm doing what I should be and I still gain more than the 15-20 I was shooting for I will think that is what my body was supposted to gain. Exercising is being added to the top of my priority list. I can do it. I just have to get with the program!!