If you suspect you are pregnant take a test, that is the only way to know for sure
you can take one 3 weeks after sex occured or once your period is late, which now would be the time to do so.
Until then, try not to worry about the what ifs and what you might do if you are. Try not to stress, try not to look for symptoms, they will only trick your body into thinking you actually are when you might not actually be pregnant.
Good luck