Am I pregnant or not???

After my first child in 2006 I had the Mirena put in, for me that made the most sence. The end of July 2008 we decided to try for another so had it taken out on the 24th. about 3 weeks later I had some light spotting but nothing hardly noticeable. Of course at that point I took a test b/c I didn't know anything about my cycle. Then next period started on 8/19 and only lasted like 5 days. Then as of today 9/19 I still haven't started. My online calendar says 4 days late but test says no. I have tryed the early test's 4 and 1 day before I should have gotten my period and still nothing. I didn't take one the first day that I missed this is my first since the earlies. I have some symptoms but not alot. I get nauseated at different points during the day espicially if I am hungry (I never did this before or felt nasea, also with my first I had it only when I went into work at 5:30 in the a.m. the day I stopped going in early the nasea stopped.) My breasts feel tender sometimes but not always kinda like a heavy tender. I was also watching what I was eating alittle (giving up pops and candy) and was loosing like 1 lb a week and have now gained back 2 in 2 weeks. Am I pregnant or am I wanting one so bad that I am making my self this way.