I think my girlfriend is either cheating on me, or doesnt like me anymore :( what do i do?

Hey, i think my girlfriend is cheating on me, or just doesn't love me anymore....if someone could help, i would really appreciate it. heres all the info i could give you. Me and her met in the weirdest way ever and we love each other alot! we have been dating for 2 weeks now and everything is going a little fast. me and her have seen each other naked and stuff and have touch each other junk and all but nothing too bad. we always talk about getting married and having kids and she asked me if i wanna be with her forever and i say hell yes.....but recently she talks to me less, talks to other guys hang with people other then me...and i just dont know what to think of all this anymore :( i posted this because today she texted me say hey im taking a shower brb and that was 4 hours ago... idk