WHERE IS MY PERIOD???

Alice
Okay guys so for last like three years by period has been like perfect. It came once a month, lasted for 6 days and I pretty much could pinpoint the exact day and time I'd normally get it (cause I always get it in at night) so my period was due to start the other day and I'm like sweet as, and then I get a little bit of brown discharge and I'm like okay cool here we go. And now all I'm getting down there is nothing but like a tiny bit of brown discharge for the last two days? I'm not on birth control and I'm sexually active but the brown discharge has started when I'm supposed to get my period? So I'm like is this just a really, really reeeeeally light period or am I having possible Pregnancy symptoms? Haaaaaalp