For the past few weeks I have been randomly getting nauseated after eating certain foods and will have a dull headache from time to time. My last period was on Jan 31st,. My husband and I had sex on the 12th and on the 15th. I have taken two hpt both negative. The first one was taken around March 3rd, the second was taken on March 6th. I do have lower back pain from time to time. These are symptoms I had with my first son, however, I still have no achy breasts and no period.