Tips for water retention

I’m 7 weeks into a prep for a bikini competition that’s the first week of June. Last Tuesday I weighed in at 134lbs. The very next day the scale went up to 139 and it has been sitting there for a week now. I assumed it was water weight and have been trying to drink a lot of water- nearly 2 gallons a day. But it doesn’t seem to be changing anything. Tips advice? I just want to be able to keep track of my progress