I Had Sex Sunday, It's Now Friday And I Haven't

I had sex Sunday, it's now Friday and I haven't came on my period, I'm stressing which coulds be the reason for me not starting but, I''ve been peeing a lot which happens regularly. I was wondering if I'm pregnant and if I go on the pill will that help. I don't feel sick or dizzy my boobs don't feel sore or tender I might just be stressing, I'm 16.

But do you think I'm pregant