Water Intake Change

The first 8 weeks I started on MFP it was very easy to drink 12 8oz glasses of water and on some days 15 glasses. I wanted it, I craved it, I drank it like it was going out of style. However, in the past 2 weeks I've found I'm not as thirsty and push myself to drink 12. Is this normal or a phase? Were the 8 weeks what my body needed to flush my system (so to speak) of all the soda I'd been drinking all these years? More curious than concerned at this point.