Am I?

I had a Depo. shot about 9-10 months ago, it wore off around Dec. I never went back in for another.. My fiancee and I have unprotected sex often. I havn’t re-started my Period since my Depo wore off and usually in the times before it has come back withen 2-3 months, but nothing yet. I buy a home pregnancy test every month, they are always negative. But lately I have been feeling very tired, I have been getting up late and falling asleep easily, I feel bloated and it seems my clothes are getting tighter, mainly around my waist and thighs. Lately in the car just driving down the street to the mini mart I get almost car sick, been feeling dizzy and just kinda "blah" been also been breaking out lately on my face and back and before I have always had a perfect clean complexion. I bought a home-pregnancy test last night (a cheap one) and it didn’t work, nothing showed up in the little windows. I have two children ages 7 and 2 and each time I was pregnant with them, I just seemed to know before I ever had tests and I never had any symptoms until around 6 months along (didn’t even show) and I continued to have my period with both my children all throughout my pregnancies. I just don’t know what to think with my current symptoms. Does it sound like I might be? :S