Lack of something in diet?

Lately I’ve been drinking a lot of milk. Like usually (before I got pregnant) me and my hubby would have a 4L milk jug last us a week maybe even a week and a half but now just by myself I can drink that 4L in three days. I feel like I’m going crazy- has anyone else experienced this? Or something similar where they ate a lot of the same thing or drank a lot of something?