Reoccurring UTIs

Anyone else getting reoccurring UTIs? I've had a couple already and am getting very frustrated. I drink a gallon of water, sometimes more, a day. I just bought 100% pure cranberry juice to start drinking as well. I don't know what I'm doing to get these. I do take the medicine my dr prescribes but really don't want to be taking meds the whole pregnancy. Especially since there's warnings against taking it in the third trimester, which I'm almost there.
 Any tips to stop these from happening?