Havent got period post sex ~40 days late

I had sex on 10 July and 26 July (different partners, both with protection). The first time he finished, but in condom, and second time, didn't finish. I haven't got my period since then. I'm 40 days later today. I took 3 pregnancy tests - on August 11, 29 and 31, all of them were negative. In this week, I was down with Fever, Cough and Severe headache for 3 days. Fever was high on first 2 days, reduced on 3rd day. 3rd day, I started feeling a bit nauseated, was about to puke twice, but couldn't. Mild pain in left breast in the morning, but it went away by evening. Should I be worried about pregnancy? P.S - I have a stressful lifestyle due to work and additional stress about this. Please help 🙏🏻 The attached pictures - light one 31 August, dark one 29 August. Couldn't attach the 11 August one.