Please read/comment* Neg test but symptoms

I want to start off by saying yes I know if you get a negative then you are not pregnant, too early, or something else going on... but I wanted to hear other women’s experiences with what I’m feeling

Backstory on my cycle, I’ve always been pretty regular I am usually always at a 33 day cycle and when AF starts it’s for 6 days

So I never actually confirmed O, I just used Opk’s and cm. I got a positive opk on February 8th-11th and when the opk started to fade I stopped testing, I did have a period feb 21st-24th. Now I usually have a 6 day period but it was similar light days 1-2, medium heavyish day 3 and light again 4. Usually I have one light day then 3 very heavy hays and the remainder is spotting for 2 days.

Since March 3rd I have been feeling so nauseous, and have had headaches off and on. I have also been feeling fatigued. Today I felt a little crampy on my left side. I did take tests February 18th until I started bleeding. And again today both negative.

Has anyone had this happen before? What caused these symptoms? Were you pregnant and just didn’t get a positive until later on/how long?

Thank you for reading this long post❤️