My period cycle is never late, it is extremely precise. It is every 21 days and last exactly 8 days. My last period was from July 31st-Aug 7th. I will make a list of all the days my fiancé and I had sex on but keep in mind, the ONLY days he came inside me was Aug 8th, he only precame the rest of the days. Here is the list: Aug 8th, 9th, 11th, 14th, 15th, 17th, 18th, and we also had sex yesterday, the 24th. On Aug 13th, I had light pink spotting which was very strange because I never spot. Could this be implantation bleeding? Also, I have headaches all day long, lower back aches, smell sensitivity, metallic taste in mouth, extreme fatigue, I feel super bloated and my belly looks bigger, I have cramps only on one side of my uterus which has never happened to me before, my areolas are a little darker, and lastly, my breasts and nipples and EXTREMELY sore to the point where even having my seat belt on in the car hurts. I took two pregnancy tests yesterday and they both came out negative. My period is still not late because it's due next week's Wednesday. Could I be pregnant?