Hi, I am 29 years old with regular periods month after month. My LMP was on 1/5/14 and I believe I ovulated 1/19/14. My husband and I had coitus before and after the ovulation date. I have missed my period by 4 days now, I have taken 3 HPT and all are negative. However, I feel different in my body, the symptoms I have are similar to PMS but these just feel naturally different. In example, I have severe fatigue I am just totally drained each day therefore unable to focus on task. I have cramping in my stomach like if it being pushed to the sides, headaches, mood swings, crying without cause, along with frequent urination, dry mouth, and at times slight nausea. Could I be pregnant or is something else going inside my body?