I am pretty sure I ovulated on January 3 (I find it difficult to tell when I do). However, I was supposed to start around January 13. I haven't started yet and my last period was December 17. I had bloodwork taken and it all came back negative. I also had surgery November 18 for my appendix and December 18 for my gallbladder. Could the surgery be causing my period to be late or is it to early for a blood test to show positive? I would like some feedback. Thanks!