confused about labor

So this morning around 10 I started having contractions about 4-5 mins apart and some SERIOUS back pain.  Get to the hospital I'm 1/2 cm dialated the monitor me for an hour she checked me again I'm 1cm dialated and she said Im having a bloody show... what does this mean? She said no baby today but I'm still in awful pain and got informed im having signs of back labor...