12 days late for AF and still no BFP?

Stephanie • I`m Stephanie, I`m 19, I`m married to my high school sweetheart and we`re trying for baby #1!
I don't chart, so I don't know when I ovulated.
​This is only our 2nd month TTC, and before that I was on BC, so I'm not sure how my cycles are naturally.
​Not sure if I could be pregnant, or if I'm just psyching myself out, or what. Advice?