so confused?

My AF was 13 days late I kept getting negative pregnancy test but my husband was sure I was pregnant and I had convinced myself also and that I just had low hcg levels and today we were going to go to the doctor and get blood work, but this morning I woke up with dark red blood everywhere so I guess af showed up with a wrath.. I've never been late before and 13 days was a long time to be late for someone who is never late.. is it possible that I had a chemical pregnancy or that I miscarried?