I'm sorry, I disagree with your mother, the pill will not prevent pregnancy that quickly. You would have to be on it for atleaast 2-3 weeks for it to be effective, atleast somewhat!! Women can become pregnant even while on the pill, especially if they've missed so many as you have.
If you had sex within two weeks of your period ending, and your pills were not being taken regularly, you may be pregnant. As far as the implantation bleeding, I've heard that it can cause bleeding but I've never used any birthcontrol devices. It sounds however, that you have messed your cycle up a bit, by stopping and starting your pills.
My best advice for you, please listen carefully, DO NOT CONTINUE TO HAVE SEX!! Your parents don't seem to mind that you're having sex and are even advising your use of contraception. Also, if you are trying to prevent pregnancy, you're going to an awful lot of trouble trying to prevent it, but very poorly. You will end up pregnant unless you stop having sex. It is only a matter of time and what you and your parents are fearing may happen, will actually happen.
You will have to decide for yourself whether you want to continue this way, or start making better choices about your relationship. If a baby is so unwanted by you and your parents...then why involve yourself in the act that creates one?? Loving a young man is not wrong.....but giving to much of yourself too soon has some lasting consequences that will change your life forever. You can love and respect oneantoher, and commit yourselves to waiting for the right time for marriage and children.
For now, I would wait until you are atleast 5 days late for your period, and then go get a blood test done. They are more accurate than the home tests and the hormone shows up in your system very quickly after your period is late. Then, if you are not pregnant.....you could possibly talk to your parents and boyfriend and decide if you want to continue going through the worry of being pregnant, having to take so many pills and possibly harming your body, knowing you're not yet in a committed relationship and still so very young. Is this really how you want to live?? Some side effects of the pill are nausea, headaches, restlessness, as well as a sluggishness, spotting and cramping. So it is hard to say whether your symptoms are associated with your period coming on early (like you said, it came on 2 weeks earlier once) or if they are related to your irregular pill use.
If you are pregnant...then you obviously have some mature decisions to make and you will have to be strong. There will be a lot of emotions overwhelming you at that point and I pray that you will accept your baby and not be pressured to abort it by your family or boyfriend. Just so you know now, there are other options instead of murdering a helpless baby. We can help guide you in the right direction if you come up pregnant....but just in case you cannot get online after the test.....Abortion is not the answer!!! There are many other young girls who have become pregnant and are lost as to where to turn. They have found help and support and decided to keep their baby and even finish high school, and are now proud young mothers who are making their life better for themselves and their little one.
My prayers are with you,
myangelsinheaven