ROCKER WIFE (or others) ANSWER PLS! HELP!!!?

Rockerwife-I was reading your answers on some other Q's and it seems like you know ur SH**. So I know I've asked this Q a dozen times but heck, i'm not getting good answers SOOO...I was on depo for 4 years and I got my last shot 3/27/08 (So was protected up until 6/27/08) me and my hubby have been ttc since sept. 18th (2008) but I don't know what my chances are considering I was on depo for 4 years. Lately Ive has some funkyyy things going on with my body though- sore bb's,occasional nausea (especially last night!!! my husband was clean and the CLEAN smell of him MADE ME ILL), i've has headaches, tummy aches, GAS =0S, but I was tracking my LH surge.. never got one (but I missed a week ;0/), and I took a preg test the 3rd and 5th and got BFN's! IDK what to think?? What should Ido? I just don't feel like myself and I havent gotten a period in 4 years (except that 4 day bleeding I got in August of this year) so I DONT KNOW WHEN TO TEST. Someone please help me out.