What Causes Delay In Periods?

Hi my name is bree I m 17 1/2 yrs old. For about a year now Ive had ITP. I have a low platelet count and don t know why still. I ve tooken steroids, IV-IG. I ve tooken a lot. But lately my periods been really light. I have been sexually active. my period last month was light. We re now in March and my period hasn t come yet it was supposed to come around the 10th. And hasn t arrived no signs it s coming....nothing.. I ve never wanted my period so bad.. Lol.. Like having my period is a good thing lets me know my body is ok and getting better. Could me not having my period mean I m pregnant or is it because my blood disorder. Last platelet count was: 59,000