Is this a missed period or am I pregnant

fay

Help, I had sex on my ovulation date July 9 and my period came on July 20th but it was a weird period so I paid it no mind. I didn’t have sex at all the month of August but my breast has been so sore, I am having weird period cramps with no period and my back is killing me. The app is saying I am 3 days late. I want to take a test but I don’t think I can take another negative test right now.