Hi Deepika, Birth control pills are very effective in preventing pregnancy if used properly. However they do have some side effects and cannot be used by women with certain conditions like liver and heart problems, breast cancer etc. In addition minor side effects are nausea, vomiting and weight gain. These tend to disappear after repeated use as one gets adjusted to the pills. However they provide protection against ovarian cancer even after the pills are stopped and are excellent in providing contraception if used correctly. So you will need to see your gynecologist, get and examination and blood pressure evaluated and then get pills prescribed. The newer ones like loestrin and femilon are all low dose and have lesser side effects. The pill must be started from day 1 of periods and taken every day at same time preferably at night after dinner. For a 21 day pack, pills are taken for 21 days and then 7 days, no pills, when the periods come. For 28 days pack, pills taken every day and last 7 pills are dummy pills when the period comes while on these pills. If one pill is missed take it as soon as remembered and take the next pill in its usual time [may mean 2 pills in a day]. If more than one pill is missed, another method of contraception must be used for next seven days. More than 3 pills missed, they will not be effective and use other method until new pack started. Irregular pill intake will cause irregular periods. Hope this was helpful. Feel free to ask any more queries. Thanks for using HCM. Dr Nilajkumar Bagde Consultant Obs Gynec