You really need to contact your healthcare provider. Remember changes in your life, medications, ect... Can all lead to problems like this--or it could be the sign of something worse. May sure to inform your healthcare provider of any medications, over the counter or prescription you are taking along with any vitamins and supplements.
If you cannot afford to your to your healthcare provider/do not have insurance contact your local Planned Parenthood, reproductive clinic, or free clinic. They should be able to help you for free/reduced cost or with a sliding fee scale based on income. If they are unable to help you they should be able to refer you to someone who can.