Watery discharge

Advice please!! Yesterday I had a big wet patch in my underwear which didn’t smell like wee (lol) and I had just been to the loo before I had the gush so I didn’t need a wee. Waited to see if there was more and there wasn’t much. Today I stood up and there was a big trickle of watery, milky coloured liquid down my leg (no I have not had sex lately!) - does anyone know what this is? I’m guessing just discharge but it’s just so watery and coming in little gushes, so unlike my normal discharge that it’s got me all on edge! I’m 37+3