Missed my whole period and theyre usually regular. So worried. Please help

Ok so usually i have 5 day periods i was due to get them on the 16th jan but they were a no show. On the 4th, 5th of jan i had a medium amount of brown like blood on my panties , on the 6th of jan it was a smaller amount but that was it. Now its the 21st and im freaking out because i got a negative from the doctor today but what scared me the most is there was blood in my urine. Hes arranged for an ultrasound tomorrow. Anyone else have anything like this or have any advice??