TMI !! Please help !

Soooo this has never happened to me before . My period is supposed to start tomorrow but I’ve been cramping and sore breasts but the first day of my period is ALWAYS heavy. I’ve never actually “spotted” before in my life . I’ve had 2 healthy pregnancies via c-section with no pregnancy symptoms and did not spot with them or have implantation bleeding. my app says I’m 16 DPO but Could I have ovulated late ? I’m an irregular girlie so it’s hard to track it. Took a few tests but i can’t see a line so they were negative and i literally slept until 1 PM today 🤦‍♀️ I never sleep that late. Also, I had a chemical about a month ago . So I’m hoping this is good and It means there’s gonna be a baby coming 🥹🙏🏻 but if anyone else has had this happen please help . I’m confused 😫