Missed period but still not pregnant!

Caitlin

My husband and I had unprotected sex four days after my predicted ovulation. And a couple times more in the following week. My period has been late for seven days and I took a pregnancy test on the fifth and six day after my missed period and they are both negative. I was experiencing cramping like I was going to get my period which I’m now assuming might be implantation cramps but I’m still negative on the pregnancy test. Anybody have any any advice?😅❤️