Pre TTC weight loss

I am trying to get in the best shape I can pre TTC so I can try to stay as healthy as possible throughout pregnancy. Plus I’m terrified of not being able to take the weight off after delivery. I’m 34y/o, 5’6”, 160# so just on the cusp of an “overweight” BMI, but would love to be able to get down to the 140s. I have successfully worked up to consistently hitting the gym 4x/wk, but no weight loss yet. I know I need to get my (pescatarian) diet in check, but any other advice would be much appreciated!