Confused!

I’m a week late for my period going on week 2, I took a test 3 days after my period would of ended and it was negative...my nipples are sore I have CM that I don’t normally and light to mild cramping and pelvic pain..took another test today 7 days after missed period and negative again! I used a $1 store test so I’m not sure if that could be a problem, or if I have something else going on! Anyone else get these symptoms and not pregnant?