Stressing if I'm pregnant

UPDATE 3: September 7th, no blood. Still having negative tests and period is due in 3 days. Super stressing out. Tired of the being let down by tests, but I feel that I am pregnant. I just need confirmation!

UPDATE 2: September 5th I had very little spotting. Today, September 6th, there was more blood. Still not enough for me to say it's my period, but enough for me to stress about. I have a sharp cramping feeling on my right side. I've run out of pregnancy tests, so I'll have to test later.

UPDATE 1: I tested this morning, September 3rd, and it looked negative. Later went to bathroom and I had a small amount of blood in CM. Pulled my test out of the trash to double check. It looks like it has a vvvfl, but it has been several hours. I will test again tomorrow morning.

My last period was August 13-20, fertile window was August 22-28. Had sex on 24th and 27th. I feel I might have ovulated on the 25th because I had a sharp pain in just my left side. My predicted ovulation was the 27th, when I had sex on this day was also the only time I seen a little spotting, not much to assume too much. From the 28th til now I have had constant cramping and lower back aches. The cramping is mostly on the right side, though sometimes I feel a twinge on the left. Depending on when I may have ovulated, I am 7-9 DPO. My next period is due in 7 days. I have tested too many times already, all come back negative. Is it still too soon? Has anyone had cramps last this long?