Can my late period be caused by stress?

Dear Ask The Doctor: My boyfriend has varicocele, and has been told by his doctor for years that he is sterile. However, my period is currently one week late. Two weeks before my period was supposed to start, I had some extreme financial stress. The next week, I was dealing with the unexpected death of a childhood friend. I was also unable to eat during the week I was dealing with the death of my friend. My breasts are sore and swollen, and have been since right around the time I would ordinarily start PMSing, so for about two weeks now. My last period was four days early, starting on the third of February, and ending on the seventh. The last time I had sex was prior to the onset of my last period. I am not experiencing any other symptoms of pregnancy that I have noticed, such as morning sickness, increased sense of smell, etc. I am extremely susceptible to pregnancy hormones. When I was on birth control, I had to take the low hormone brands because the regular brands caused me to be violently nauseous. As a result of this, I am inclined to think that I would be experiencing some level of nausea by now if I was pregnant. I know that stress can cause a missed period, but I guess I just want to know if the tenderness in my breasts would also be considered a normal side effect of a stress induced irregularity. I am going to take a home pregnancy test at the end of this week when I get paid, but some advice in the meantime would be helpful to ease my mind, one way or the other. Thank you in advance for your time and consideration. Cassie

Dear Cassie: I do understand your concern about being pregnant, however it may be unlikely taking into consideration the timing of your last sexual intercourse (which you've said was prior to the start of your periods). Stress is indeed a factor in many who have delayed periods. However it is a good idea to do a pregnancy test anyway. I wish you well, take care.