So my last period was on June 19,2017. I ovulated on July 3.expected period is July 17th. I've been testing since 8DPO and all have been negative. But Saturday I started getting brown in my cm, and then the next day just a liner spots of brown. And now today nothing? Is it possible it was implantation bleeding?? Isn't is a little late for that? Because my periods are usually red and heavy. Do you think I should just give up and try next month or should I keep testing?