Pumping while ttc, pregnant and maintaining supply?

Hello my baby is 3 months old. My husband and I plan to try for baby #2 when she is 6/7 months. I exclusively pump due to poor latch and get 50 or so ounces a day pumping 5xs a day (but it takes an hour per pump, 15minutes just to get a let down). My question is can I still pump when pregnant without issues? And if so with the next baby (if same milk transfers issues are there) I need to pump 2-3hours for 12 weeks again or will my milk simply just change and I can continue 4 pumps?