late period..

so, my period is 2 days late. a week ago i took a pregnancy test and got a very very faint positive. a few days later took another test from a different brand and got a definitive negative. I am so confused. I have had all PMS symptoms for about a week or so now. ive had mild cramping for a few days in my uterus. I feel like i have my period but nothing is coming. The only thing that is coming is what seems to be like a milky looking discharge on my panties. has anyone every experienced this or have any ideas of what the hell is going on?