Confused

I currently slept with my partner. 24/09/2017. Where I was ovulating my period was 11/09/2017. I then slept with him again on the 7/10/2017. My period was due the 11/10/2017. I came on the 10/10/2017 for 2 days very light blood pink/brown. (My periods are normally really heavy) the bleeding was lasting up to around half an hour a day. My period in November was due on the 11/11/12. I am now 8 days late with negative tests too.