Negative test...not sure what to thing...

Callie • Workaholic. Irish. Owns horses. Traveler. Rig welder. Blacksmith. Paleoholic. Gypsy soul. Can`t be tamed
So I have a boyfriend and we are active. We use condoms cause I don't have health care. Sometimes my period is on time (with in 27 days) and sometimes its late... This time I'm a week and a half late. So I took a pregnancy test and it showed negative. Not sure what to think. Any ideas?