Late Period

So, I'm getting kind of worried now. I'm late by 18 days so far. I'm a virgin so can't be pregnant even though everytime I'm late thats what my brain immediately thinks. Once a day ago or two when I wiped I had a very faint pink to it and some of the sticky blood which are the blood cots right? Before that I had a some old blood stuff every now and then. I was wondering if I should be worried and schedule a doctors visit since this is the latest I have ever been.