Help! I'm a little worried

I'm due on AF tomorrow but I've been getting period cramps for the last week on and off (no spotting or bleeding) including a backache every now and then too. If I don't come on I will take a pregnancy test tomorrow but I am worried if it is a BFN just because I'm scared something could be wrong with me. This is only my 2nd month TTC but I've always had that feeling. Has anyone felt the same?