Hi Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concern... Delayed periods with severe headache can be indicative of pregnancy if you had unprotected intercourse since your last period. Headaches, nausea, vomiting like feeling morning sickness, etc can be symptoms of pregnancy. In that case you should do a pregnancy test first. As you are a month late on your period. A urine pregnancy test is sufficient to know if you are pregnant or not. You could do this at home by a home pregnancy test kit. Preferably this test should be done at morning with first urine sample. Follow instruction written on pack & add your urine to it. Presence of two red lines on kit will confirm you are pregnant. Refer to a gynaecologist Hope this information helps