Hoping your appointment goes well, I'm sorry you're going through this! No advice here, but plenty of virtual support. Not a pleasant place to find yourself, and I hope you can get some rest tonight. It's a VERY good thing that we have all the options available to us that we do.
Depending on how far along you are, you may likely be a candidate for a medical abortion as other posters have mentioned. They use two drugs most commonly; Methotrexate (a chemotherapy agent that inhibits folic acid and thusly doesn't allow cells to replicate) and Misoprostol (a synthetic prostaglandin E1 analogue. It causes uterine contractions). Methotrexate is given orally and Misoprostol is given either orally or vaginally depending on the clinic and clinician. It is not a pleasant process, especially if you haven't been on either of those drugs before for medical reasons (I was fortunate, I had prior experience with them).
Unfortunately, a pregnancy test can provide a false negative (ask me how I know...), but not a false positive. Wishing you all the best and lots of hugs and support. You'll be fine, it sounds like you are making the very best decision for yourself and your life.
OP, while I did not terminate, I know what it feels like to take BC properly and be the 1 in 100. My son was completely unplanned, and my DH and I were not yet married. It is such a scary thing.
Like someone else said (as someone who has now had two surprise children... both on birth control, the pill and IUD)... it can be a false negative but not a false positive so likely they will confirm what you already know.
I fully support your decision and I am here if you need to talk, feel free to shoot me a PM.
Hugs to you. Take along a really good support person, tomorrow, if you can, and when you go for the procedure.
If you read my post on the other thread, you'll know that I too am Christian and pro-choice. Also, that a part of my job description is to work moms suffering a variety of perinatal losses. Here are links to the only two places I send women who want post procedure support: http://www.afterabortion.com/ http://exhaleprovoice.org/
Too many are only "pro-life" fronts and lay too much guilt.