pregnant ?

okay so i had unprotected sex march 24th (pull out method). i was supposed to start my period 3 days ago. i’ve never missed or even had a late period. i had some spotting yesterday so i put a tampon in bc i thought i was ab to start. i pulled it out after a few hours and only saw old dark blood. i’ve had a few cramps & my boobs are swollen and really tender but other than that i feel fine. i need some advice asap bc i’m really stressing.