Am i pregnant or not?

Hey girlies! so i have a question. I'm a girl that has irregular periods and me and my boyfriend have been trying for a baby for like 4 months now but it's so hard to track my cycle and everything because of my irregular periods but we had S** on the 11th september which on my cycle app said it's the highest chance to get pregnant, So after 3 weeks i have pregnancy symptoms my boobs were really really sore and i had cramps in my abdomen & then i got my period 3rd october but bare in mind i never ever had periods shorter then 7/8 days and this time i had my period for 4 days and the last day it just stopped out of nowhere & idk if it was spotting or period & ive tried few tests and they all came back negative! pls help🥺