Early pregnancy symptoms?

My last period was on June 13th, 2016 and last approx. 5 days. My husband and I had used no form of birth control for 2 years now except the "withdraw Method". On our wedding night, June 25th, 2016, we both decided it was no longer necessary so he ejacuted inside of me. On July 11th, 2016 my next period was due. It never came... And now I'm almost 6 days late. I have taken multiple pregnancy tests, before and after my period... All negative. I have read a positive may not be detected until a couple weeks after a missed period but not hopeful I am pregnant. I went to the restroom this evening and saw a tiny bit of pink-ish blood and thought I had started my period. It has been 4 hours and no bleeding since. I looked at my ovulation days and they are June 25th-29th. What does everyone think? 5 negative tests but no period. I have had lower back pain, cramps, diarrhea, but this could all be signs pointing to an upcoming period. I am usually 28 days or sooner. Never late.