light period!

Leanne
Just needed some advice... 
I was due my period on Friday however it didn't come, yesterday I was at work and when I went pee there was pale pink spotting! My thoughts were oh well not this month again :( I had kind of got my hopes up a little as there had been some symptoms of pregnancy such as fatigue, back pain and Indegestion (which I have never suffered with) this morning I woke up expecting to be very heavy as always and it's a rush to the toilet to change although to my surprise there was only a spot of pale pink on my sanitary towel sorry for the detail! I bathed and changed and all day there has only been a very light spot how can this be? Where is my normal period and what's happening???? HELP!! Xx