My cycle is normally regular. I am not on any type of birth control. My cycle usually begins on the 15th or 16th of each month. Well, on last month, my period came on Feb. 23rd. It only lasted 3 days. It scared me, and I thought I was pregnant. Well, my doctor informed me that my cycle should definitely begin on the 23rd of this month. My cycle hasn't came on yet. My doctor gave me an ovulation calendar. He said, a pregnancy test should show whether or not I'm pregnant. I am having certain symptoms like tender breast, fatigue, nausea, and I have to go to the bathroom almost 30 times a day. Could I be pregnant? Are is this all in my head?