I've always amped up my workouts beforehand to build muscle when getting ready for pregnancy. Last time I got pregnant a bit before planned. But I wasn't as careful as I needed to be if I wanted to prevent that badly. Having 3 months of more intense than normal strength training has done me well as far as preparing for gestation. And taking vitimins too. I figure that the harder I work before is the easier it will be to bounce back after as well.