Maybe pregnant? Wtf is going on.

So, been with the same guy for 5 years. We don't have very much sex anymore. We havent had sex since Aug 18'th (Today is Oct 2) and I am 10 days late. Now, my first thought is "I'm pregnant." I've talken 6 pregnancy tests all negative. Wtf is going on? It would show up by now, right? I did move to another state and have been working a lot more, but 10 days is nuts. Not too mention my uterus feels bigger (I know TMI). Any thoughts?