If you miss your menses date by more than a week, the first thing to check should be pregnancy, do a home test. You get many types of pregnancy checking kits in chemist shops. Buy one and check with the first urine early morning. If positive see a Gynecologist (obstetrician in delhi) at the earliest.
If your age is more than 35 years (which is quite common these days as women are now career-oriented) then you are a candidate whose pregnancy falls into high-risk pregnancy group as with advancing age there are more chances of problems for the mother and the baby both. Similarly, if you have got your pregnancy after treatment for infertility or through IVF (test tube baby) then also you come into this group.
Follow the advice of your Gynaecologist sincerely and carefully. Go for regular check-ups. Do all the tests asked for as in these pregnancies some extra tests are needed most of the time. Take all the prescribed medicines regularly