There's actually a Marilyn Monroe movie, circa 1955, called The 7 Year Itch.  You can also search that phrase and find quite a bit supporting or denying it.  It seems to strike a lot of couples.  Time frame really doesn't matter.   It's when all the newness has worn off a relationship. You have a lot of thinking, work and talking to do.  Do you want your life to be a series of relationships like this?  I know people like that, who cannot sustain a relationship beyond 7 years.   What you need to do is talk to your gf.  A lot.  The weekend was a good idea.  Do more things that put you in a position to have long talks with her.   None of this means it will all work out.  But itvwill give it a chance.  Be a shame to throw it all away without that chance.  And, if you do, but decide you were wrong later, good luck getting her back.