I typically have my period every 28 days. I am now 14 days late. I have taken 4 pregnancy tests all of which were negative and had a blood test done which also said that I am not pregnant. Does anyone know what could be wrong with me?

I typically have my period every 28 days. I am now 14 days late. I have taken 4 pregnancy tests all of which were negative and had a blood test done which also said that I am not pregnant. Does anyone know what could be wrong with me?
Depression or stressed out it happens to my sisters all the times if your life is very diffacult at this time from school or a boyfriend or work, take a couple days to yourself don't go to work, don't go to school, and don't see your boyfriend and you'll be back to normal in no time!! Just remember to take it easy, and relax.

My life is rather crazy right now. My husband is in the military and deployed. We are living overseas and I have a challenging two year old. We are also trying to get pregnant and I am stressed that we are never together to give baby number two a shot. I also feel depressed. I miss my husband, my family and am having a hard time making friends. Also life in a new country is hard with a toddler. I wonder if I am truly depressed enough to need help. If I lost my period due to stress and depression I guess that is bad enough? I am not sure if I should talk to a doctor or not.