worried and wondering

my ld fiance were sexually together between march 29th and april1st, i had some light brown spotting about the 11th, i was due on the 17th, still nothing, last night i needed to go to the ER, they did a urine on me and it came neg, i have done home tests also and got a neg result. i have been more tired than usual lately, and have this terrible feeling of fullness, like after thanksgiving, i find that i pee alot, and i have just felt ‘weird’. could it be that the test was still too soon and i could still be pregnant? or is this maybe due to me stopping using the nuva ring? any suggestions would be a great help. thanks!