A vaginal discharge worry?

My period was due 16th May but it has not come. Yesterday i was getting alot of wetness when I wped and today it felt as if i was 'on' as the feeling of blood was felt. However, when I went to the toilets it was just discharge and then when i went for a poo i looked down and there was a long line of discharge (like when you can see blood coming out) So I am so scared as I am only 14 have not had sex and this is the first time it has happened!