Weight gain

Anyone have experiences in being overweight before pregnancy and gaining about 30 pounds then loosing it after the baby is born? 
​For instance, I'm 5'5 and weighed 173 when I found out I was pregnant, then I dropped down to 166 but now I'm up to 184. Just wondering how hard it would be to drop back down to the normal weight for my height which is around 125-135. But I plan on doing it the healthy way and working out!