13 days late

My period is 13 days late but I’m a virgin. What should I do? I’m too scared to buy a pregnancy test because I’m shy and my mom would murder me. There’s no possible way I’m pregnant because duh I’m virgin and I had no contact with semen. However the last three days my boobs have been getting sore which is a common PMS symptom I have before I get my period. So is it coming? I tried the home sugar pregnancy test remedy and the sugar dissolved which means not pregnant. But