My cat has been losing mucas for a couple of days now, do you know when she will start begin the second stage of labor - she has been having contractions.

My suggestion would be to call a vet and ask. My cats normally don't let me know when they're going to release their lttle bundles of terror upon the unsuspecting world... they just do it (in my craft drawer, on my yarn, under the couch, on my clothes) best of luckto you and kitty.