Exercise

Ever since I found out I was pregnant, that didnt stop me from being active. Usually I will swim once or twice a week for 2 to 3 hours but now is the fasting month and by the time I break my fast, it's gonna be abit too late to head to the pool. Was wondering if there'll be any significant changes if i stop exercising for like a month and then continue after fasting month is over? I'm not gonna lay in bed all day obviously, still gonna eat in moderation & walk around. Swimming is the only low impact sport I can think of that doesn't kill my back since I'm carrying another human inside of me. Any expertise on this mommies?