am I pregrent?

Hey ladies so supposedly I'm 17 weeks late of my period from a different app I used called period tracker  . I had sex on December 8 . And I haven't had my period but I haven't had any pregrency symptoms I been searching up for symptoms so far I haven't had any . I took a pregrent test and it was negative . Should I wait longer ? Or should I go to the doctors? I could be pregrent since the first sign of pregrency is missed period . Or should I wait much longer ? Oh also I am irregular when it comes to periods .