What Causes Clear Vaginal Discharge?

I have had a clear (yet sometimes with an undertone of red and brown when i wipe)watery substance leaking from my vagina since ending my period just over a week ago. On the east day of my period I had sex. Which restarted it a bit. And since then have been leaking this fluid at least twice a day?? It sometimes has what I can describe as an acidic smell..