PLEASE HELP!! Pregnant or What?!

So, I need some help... I've been taking birth control, but have not been consistent with it in the past. My last period ended on May 30. My next one was supposed to start June 25. On the 22nd of June, I wiped and there was very very light pinkish/brownish discharge. On June 23 and 24, the same thing occurred but was associated with dark red/brown clots about the size of the width of a pinky nail. There was no more bleeding or anything after that. Usually when I get a period, it's rather heavy for 3-4 days. So, I decided to take a pregnancy test on June 26-28. They came in a pack of 3, and each day it was negative. Since then, I have experienced no cramping or any other period symptoms. However, yesterday and today (July 10 & 11), I've been experiencing sharp cramps in my abdomen and lower back and also very sore breasts. According to this app, I supposedly started ovulation today. Should I take another pregnancy test even though I already had 3 negatives? Was that tiny amount of blood and clots my period? Or did my body just decide to give me a wimpy period? Any advice and opinions are greatly appreciated!