Everyone else has given you answers about what could be going on, and I agree with someone else on here: if your child is, miraculously, still alive, then please consider what a great blessing you've been given in having a second chance. But it's not very likely that your child survived.
I just want to let you know that there is healing for post-abortive women, when that time comes for you. It will come. Some women deny it, some bury it so deep that they become numb to it, some become very bitter, but in a year, a decade, three decades--whatever--you will have to face it. Nobody on here will talk to you about that, but I feel it's very important because most post-abortive women feel silenced by society, as if they aren't allowed to admit that it hurts. You can't ever heal until you face it and admit what happened, and that is a very hard thing to do, but that time is available to you whenever you are ready--today, tomorrow, whenever. God loves you unconditionally, will forgive you, heal you and restore your dignity and self-respect, which abortion ripped from you. This is just one http://www.hopeafterabortion.com/ of many post-abortive counseling sites. You can look for more. There are also hundreds of stories by post-abortive women here http://www.silentnomoreawareness.org/testimonies/index.aspx , where you might find some inspiration to seek the healing you need.
I wish with all my heart that you had known there were non-violent options for you which could have spared you all of this anguish and let your child live. Please know that there is such loving help for moms in need if you find yourself in this situation again, and it's all free. Did you know that? Did you know you could have gotten help with housing, employment, legal/financial/medical aid, baby items, and everything else you would have needed, plus emotional support, all for free? http://www.birthright.org/htmpages/locate.htm
This site http://www.abortionincanada.ca/health/index.html can help you understand the trauma done to your body through abortion, even a medical abortion, and the possible consequences you may face. One such consequence is a 40% increased risk of breast cancer even with one abortion http://www.abortionbreastcancer.com/press_releases/100106/index.htm , so if you are on the pill or another form of hormonal birth control, do yourself a favor and get off of it, as that alone increases your risk of breast cancer by 3-4 times, in addition to the 40% increased risk due to the abortion. I am not trying to scare you, but to inform you so you can make healthier decisions in the future. Abortion does awful things to a woman's body, yet no abortionist is going to tell you this.
You and your boyfriend will have a lot to face because of this abortion; it will not make your relationship stronger, but worse. It's a reality that over 70% of couples who abort end up separating shortly afterwards. If your relationship is worth saving, you both need to turn to God together in some way, face what has happened and seek counseling together. Abstaining from sex in order to regain your self-respect and to learn what sex is truly all about will aid you enormously. It will give you the freedom to take a breath, stand back, evaluate the relationship and notice problems that need to be worked on, a lot of which are hidden when sex is involved. Please see this site http://www.chastity.com/node/21 to help you better understand what I'm talking about. Children are the greatest blessing on loving sex, and you need to discover that in order to have a happier future.
Your child will forgive you if you ask, and asking that forgiveness from God and your child, whenever you are ready, will help you begin the healing process. Many women find it helpful to write a letter to their aborted child, name the child, and plant something in honor of him/her. It's never too late. I will pray for you to find comfort, healing and a new beginning. We have all done things we wish we hadn't done and we are all allowed another chance.