Need advice

Kayla

Okay, so I'm on birth control and have been for over a year now and so me and my boyfriend don't use condoms. I'm 2 weeks late on my period, but I've taken a pregnancy test and it was negative... what could be causing my period to be so late?

UPDATE: it's now been almost 3 weeks and just yesterday I experienced very light (didn't even have to use a tampon) spotting, that was super light red and light brownish... just a little concerned