Irregular period/spotting/blood pregnancy test

Mary catherine

So I have irregular periods and my last period was July 1 only 4 to 5 days and and it’s so weird for me because it’s hard for me to know when I’m ovulating but close to the end of the I had sex and like a week or 2 after I spotted and I got a blood pregnancy test like at the end of last week and it was negative but now it’s August 12 and I haven’t started my period.

I don’t know what to think?? Need advice??