What's up with this white discharge?

I've been having lots of white sticky discharge (no smell or itch or anything) �lately and it gets on my undies as well. I'm wondering if its a sign of my period coming soon (had it may 19). I had sex about three weeks ago and used a condom. I'm just paranoid but I'm wondering if white discharge means menstruation is coming or something else?�Btw when should my period for this month have been I still haven't gotten it? I am very irregular.