Trying to figure out what to do next?????

Its a long story, so i'm trying to make it as short as possible... :)

May 2011- Got pregnant.
July 2011- Had a miscariage, and had to get a D&C
Aug. 28th- Started my 1st period after D&C

My periods are usually every 3 weeks and last 3-4 days.

Sept. 16th I moved to NC to live with my sisters. I was expecting my period within the week of the Sept 18-24, but it never came. I figured it was the move and I would probally fall into my sisters cycle.
Sept. 25th I took a test, it came out Neg.
Sept. 26th in the morning, I took another test, It also came out Neg.

I dont know if it was too early to test.

Today is Oct. 16th still no period. Ive been having light cramping since Sept 25th, and a little nausea within the past week.

Should I test again?