Internet suggests I'm pregnant

So my period ended early, which NEVER happens. I'm always 5 days with the same flow every single time. I am not on any type of birth control, and what the internet says is what is exactly happening but you never know if the internet is accuarate. I did have unprotected sex and he may or may have not came inside me-- we weren't sober. I took Plan B just in case but I didn't take it until after 24 hours but now this is happening. I have not been stressed or anything like that, my diet did not change. Thoughts or insights as to what is going on would REALLY help. Thank you so much