So last month I started my period on the same day I went to the hospital and was disgnosed with kidney stones (May 19). My period only last two days, which is much shorter than usual.  Last week (on May 5) my boobs started to swell and become more tender than usual.  This is normal, as this is what usually happens one week before my period begins. However, my period has not started yet and it is now almost 10 days after my boobs become tender. My boyfriend and I did have sex, but it was protected. I do not believe that I could be pregnant, but I have been under loads of stress recently with exams. Do you think these irregular symptoms could be a result of stess and the kidney stones or should i be worried about a possible pregnancy? I have already tested twice and have come up with a negative result but I'm still very nervous about it.