Its a shame, but herpes is with you for life. It is triggered by stress. In canada we have a medication that can keep the sores from coming back frequently. But since you are in sri lanka, im not sure what your options are. I really think you need to see a doctor. If this is impossible for you, then dont have sex if you can help it (if you insist, use a condom) and dont use any kinds of soaps in your vaginal area (as this disturbs the natural ph levels and causes infections and irritations) your period being late is probably no big deal, as women most of us are irregular. But, to be sure, ask a doctor. Good luck