Too early to tell?

My husband and I had unprotected sex on January 23rd during my fertile days. I was put on birth control on the 12th, but my gyno said to wait a month before it would be effective... He came inside of me, and it's killing me but its way too early to know if I'm pregnant or not. We are not trying... We won't be upset or object to it... We just weren't exactly ready right now... But I'm curious. Any thoughts?