1 day late, 15 DPO, negative test

I’ve been feeling tingling sore breast for the past few days. This is also a pms symptoms. It wasn’t a PMS symptom until I started TTC. (I guess I didn’t pay any mind before until now) I’ve been kind of nauseous and my appetite has decreased- unusual around this time for my stomach is a bottomless pit before my period. I’ve been suffering from constant headaches. I am 1 day late and 15 DPO but my tests are coming out negative. If I’m getting symptoms of pregnancy, hcg hormones would already be in my system making my test come out positive... But they are telling me I’m not pregnant 😔 why is TTC so hard?!!!