Honestly, you might be or you might not...There's unfortunately no positive way to know until you test.
With my first I remember just having sore boobs for more than 2 weeks and somewhere in between I had implantation spotting that lasted for a day. At the time I was kind of oblivious to it and thought "hmmmm...must've been a weird period" and then a week later when my boobs were still sore I decided to test and it was +. I started getting nauseous shortly after I found out...about 4-5 weeks along.
Everyone is different and experiences it in different ways. Just hang in there until you can test and then you'll know for sure. Good luck!
~Jenn~ Mom to Ethan - my heart surgery survivor - born 6/29/09