Worried I'm pregnant - advice please 😤

Hollie
Please don't judge 
I had unprotected sex on 30/03/2016 and took the morning after pill 4 hours after having sex. Whilst in the consultation room before taking the pill me and doc worked out my periods and he said I'm slap bang in the middle of danger zone. 
My next period is due at around 14/04/2016 but woke up this morning to brownish discharge? I'm really worried that I could be pregnant, but I believe the discharge could just be a side effect of the morning after pill (i took this almost a week ago) 
I have cramps and can't stop thinking about it in work I am not ready to have a baby. Please can someone give me some advice on when's best to take my pregnancy test & why I am bleeding? I'm thinking of calling the sexual health clinic helpline for some advice as I can't talk with my mum about this. Please help if you can I'm worried sick.Â