Several Times The Past Few Weeks I Have Woken Up

Several times the past few weeks I have woken up smelling burnt toast around 4:30 am. I am 67, obese, have controlled hypertension, diet controlled diabetes, hx of afib with successful ablation, sleep apnea with nightly CPAP use. I am on xarelto. Should I be worried? Have not had this during day but have had more headaches than usual especially to the back of my head and neck. B/p right now 128/79.