Like has already been said, you need to get to a doctor, start taking your prenatal vitamins and most of all tell your parents you are pregnant. It is important you are also eating right and taking care of yourself for the health of your child.
I, personally, would not be excited to find myself pregnant at 16. Are you scared or nervous at all? Especially considering your mother said she would kicked you out if you were to get pregnant. I know your boyfriend says he'll support you and the baby... but those silly boys like to talk a lot and never act upon it. Have you done any research as to how you will care for this baby financially? Not only after it's here, but while you are pregnant too? Will you have medical insurance if your mom chooses to kick you out? What about unexpected expenses after your child is here... medical bills, etc.?
How do you expect to handle things emotionally? Do you really think you are ready to live with a boyfriend already? I can assure you it will not be like playing house in the least. The baby will put a strain on the relationship like they do with most, you may fight more often than usual, while also having to manage money and school.
Babies are very emotionally draining. They wake up multiple times a night for at least a couple months and if your little one ends up with colic it may possibly spend hours of its evening screaming its little head off. Hell, even babies without colic spend a good amount of their time crying. Also, that little baby who seems so cute and cuddly in the beginning with be a toddler within a years time. Are you prepared to be a mother to this child for all through its adolescent and teenage years?
I'm just trying to say that having a baby will not equal a fairytale ending for you and your boyfriend like most girls seem to think. It will be
more than hard work, it will most likely be a struggle. I love my son and he really is the light of my life... I won't dare say I regret him, but having him has made things hard for me. I think you can ask and most moms on here will say without a doubt they would have waited longer to have their kid.
If you choose to keep the baby, then congrats and best of luck to your family
I'm not trying to kill the happiness you are feeling right now, I just want to make sure you know what a life changing decision having a baby truly is.