Pregnant??? Or?? What's wrong with me

Hey guys! So I haven't had a period since May 8th, and at first I was like oh whatever cause it's pretty common for me to get my period a week or two late. But here I am, September 11th and still no period. I've spotted both pink and brown about twice if I remember correctly. And every two weeks or so I get convinced that I'm going to get my period because I'll break out, get a little crampy, gassy, grumpy and super tired like I do before my period comes. But it never comes. My breasts have also been sore for a few weeks now, but not crazy sore just like a hey please don't touch those right now babe kinda sore. I do have unprotected sex almost every day...and I've taken pregnancy tests back in June but they're all negative except for one when I first missed my period which was very faintly positive but when I posted it many people said it was an Evap line. I called my doctor and she can't get me in until Oct. 6th. Would it be possible for me to be pregnant and not notice it by now? I think based on my last period I'd be 17-18 weeks today but I don't know how I wouldn't be showing? Just looking for advice from people who have gone through a similar situation or just know what could be going on with me. Thanks ladies 😘