7 days late for period and still negative tests

I should’ve gotten my period on 8/20 I am still testing negative for pregnancy, I’ve been testing since 9 DPO. I got positive opk’s on 8/5 & 8/6 I just now started tracking my bbt so unfortunately I have no confirmation if I actually did or not. But, today my nipples are so sensitive like they were when I had my chemical pregnancy. So confused and it’s really starting to stress me out. I’ve taken opk’s and hpt every day and both are low & negative. The only lifestyle change I’ve made this cycle is starting high dose iron for my anemia(Ferrous Sulfate 328mg) when do I contact a doctor? Could I even be pregnant at this point? Attached is all I have for my bbt chart.