I have only one fallopian tube could I be pregnant?

I am a little confused wonder if any one can help me out. I have only one fallopian tube, subsequently I always thought that I couldn't get pregnant. I use absolutely no birth control with my fiancee. My period was 2 weeks late, then i got my period it was normal and now a few days after my cycle it looks like im spotting not sure wuts going on here any thoughts?