Late period

Hi everyone me and my partner have been trying to concieve for three months now. I have tried not to get to obsessed with it all, so we decided that when it happens it happens. My last period was on March 13th and lasted 4 days. Still i have no sign of my period this month, i would now be 11 days late, took a test today and was negative. Does anyone think i may still have a chance or is it just a tormental wait for af to arrive? Has anyone had a negative at 11 days late then a positive? Your comments would be greatly appreciated thanks