Sara, it is completely normal to have an increase in vaginal CM as the pg goes on, and yes, sometimes it can be quite watery. I tend to have to wear panty liners towards the end of my pg's, but I know of many others that wear them much sooner and have more of it. There was a thread about it the other day too. I will dig it out for you.

ETA - here it is; Mum's with 3 or more bubs? Discharge?