One day late...surgery on monday(3 days)

Hello all! We have been ttc for over a year and just had our first consult with the fertility specialist last month and due to start clomid this cycle. In addition I am scheduled for throat surgery in 3 days (Monday, today is Friday) I am one day late. Suppose to start yesterday. Took a test yesterday but negative. I am due to be at the surgery center at 6am and just wonder if i should have surgery if I haven't started and still showing a bfn???