am I pregnant ?

my period is a little late but I think that's because I took a Plan B pill. I was supposed to get my period on Sunday but today is Thursday and I still haven't gotten it. I was having some symptoms of my period like my breasts were sensitive and I was bloating but now I'm not having those symptoms anymore. I also had some discharge today that looked like it had some blood on it and when I wipe myself they was discharge in a little bit of blood but I don't know what this little bit of blood and discharge means please help