Hi there, hope you are doing okay, it's been a while since you posted this. You are so young, but you showed great maturity in coming and asking for advice!
First, have you taken a pregnancy test and confirmed you are pregnant? If you are very close after your missed period, I would take the test first thing when you wake up. More pregnancy hormones are in your first urine of the day. I had 2 false negatives when I was pregnant with my son, with tests taken at other times of the day. If you cannot afford to purchase or have no way to get a pregnancy test, perhaps your town has a pregnancy resource center? You should be able to obtain a test for free there.
I don't know you or your parents, but even though it's going to be very difficult, I assume they love you very much, and will be your greatest allies in the difficult situation you are now in. I pray that this is the case for you and would suggest you tell them as soon as you confirm your pregnancy, so you can get support from the people who love you unconditionally. This is also important so that you can pursue prenatal care openly. I would choose a time when you are all at home and there is no obligation to be anywhere else for awhile, so that emotions can play out and you all have time to work things out in a safe environment.
I would not advise you to have an abortion. I personally believe it is the taking of a life, of an amazing gift (despite the circumstances). I think my opinion is in the minority, but aside from my moral objections to it, abortions can also be dangerous physically and emotionally. There are risks involved, so be very informed no matter what you choose and get your information and care from a reputable source.
Adoption is also an option to carefully consider! Giving your child, whom you will most likely grow to love and be attached to during your pregnancy, to a set of parents with empty arms and full hearts is THE MOST SELFLESS gift a mother in desperate circumstances can give to her child and also to those parents. I am in AWE of mothers who cannot care for their child(ren) and entrust them to a home that can care for them. I haven't personally given a child up for adoption, but my husband and I plan on adopting older children in the future and when we do, we would like an open adoption, one in which we have contact with the birth mother(s). There are a couple different types of contact you can choose, so there is a fit for anyone considering adoption.
Raising a child as such a young mother will undoubtedly be difficult, but not impossible- providing you have the right support system and maturity to understand that your life will now need to take a backseat to your child's best interests. My aunt gave birth to my cousin (my best friend!) at age 14 and while the journey was difficult, she had my grandma & grandpa as an amazing support system. I can't imagine not having Jess around!
Whatever you choose, there is at least one stranger in Michigan praying for you!!! May God bless you and your baby!