Anyone know what could be going on?

I had a period on July 23-26 and my predicted ovulation/fertile week was August 1-6. Me and dh baby danced on the 31st 4th 6th and 8th well but Im not sure if I ovulated as I didnt see any signs or symptoms. Well a week later on the 15th I got flu like symptoms and I felt awful I noticed my cm was clearish white and a little stretchy. Well the next day I had low abdominal cramps and low back pain and still felt awful like I had the flu or cold and my cm was even more than the first day and NO bleeding or spotting has occured either. Well fast foward to today AF was predicted to start yesterday but still hasnt shown up. Could that have been Implantation or late Ovulation? Has anyone had this happen to them?