Sounds like you are in an awkward situation. What kind of advice is it you are looking for exactly?
Seeing a doctor is THE MOST important thing right now. Not for you, but for the baby if you are pregnant.
If you are missing your period and took these pregnancy tests exactly as they are recommended, it sounds like you could be pregnant. Then what? You need to see a doctor, you need to get medical care, take vitamins (again, not for you, for the baby) and you need to tell your parents.
If you need confirmation of your pregnancy, you can go to a planned parenthood clinic near you to get FREE pregnancy testing and counseling on what your options are.