How do I know if I’m pregnant??

About almost 2 weeks ago (on the 15th) my partner accidentally came in me and I took a plan b/morning after pill a little bit after panicking, thinking it would be more effective that way. So really there’s 2 questions here.

1) What are pregnancy symptoms after 2-ish weeks

And 2) Are plan b/morning after pills more effective the sooner you take them??