Period 11 days late. Freaking out

I’ve tested four times and they all ended up being negatives. But until today, I have no signs of my period coming.... a week before my expected period I had brown spotting that lasted only a day and sometimes I get cramps that feel like my period for a short time until it goes away. On top of that I started taking meds from my dermatologist and recently had a fever, could that delay my period? Please help I’m so scared