9 DPO- 2 BFN. Still hope?

So I had an LH surge from the 14th to the 17th, an the app premom app says that I ovulated on the 17th (based on a peak LH surge on the 16th and then a sharp decline) which would make today 9 DPO. BDd all of the 4 days. Just now began to get some cramping and some cloudy CM. I’m starving. But i had 2 BFNs. Should I hold on to hope? Is 9 DPO average on implantation? Any one else get BFNs then positives a few days later? I feel defeated and just need some encouragement...