Nobody can know how you will feel afterwards. We can only tell you our own experiences. Before I tell you mine, I will warn you that I did want my baby that I terminated, even though I am very much pro chouce. So if I refer to it as a baby, please don't think I am judging anyone else's decisions. Also, if you skip to the end I have added a link to a great website for you.
Here is my experience:-
We had exactly the same situation - a split condom and morning after pill both failed. We discovered the pregnancy at 4 weeks and immediately I had to find out about termination - because our marriage was very rocky and we were trying to save it - husband desperately didn't want another child, I did. I had the choice of raising 3 very young kids alone and probably on benefits, or trying to work out the problems and save the family situation for the other two.
I chose to terminate. They wouldn't let me have the procedure until after the 6 week stage! I had to go through two weeks and 4 days of knowing I was pregnant, with a baby I truly wanted, crying and apologising to him/her. It was my birthday and Christmas during that time - so horrible. The procedure was set for Boxing Day.
At the abortion clinic I was shown into a room full of teenagers, all laughing and joking. I was crying. I felt very out of place and wasn't allowed hubby with me.
They insisted on doing an internal ultrasound, to be sure of dates and measurements before testing. Apparently a regular ultrasound isn't always accurate at that stage. It felt very invasive and wrong. I wasn't allowed to see the photo they printed.
The actual doctor was wonderful. he really cared about the situation and was clearly deeply unhappy to be going ahead with it, knowing I didn't want it, but had to go with what I said, and I insisted I had to have it. So I chose the pill method. I was given one pill then, and had to sign promising I would take the next pill the next night. I also had to promise to return within a month so they could verify the abortion had worked and that if it hadn't, they had the right to legally force me to abort as the pill can have negative effects on the foetus if it survives.
The pills were okay and after the second one I got cramps and then a very heavy period. I never was able to see any sign of pregnancy though I tried - it was just blood and a few clots. The cramping was bad, but they prescribed good pain meds.
Emotionally, it was devastating for me. I thought I was fine a few weeks later, but the following year I was totally unable to deal with the holiday season - I was a zombie, constantly thinking of the baby I would not be able to wrap presents for. I had named my baby even not knowing the sex. It also didn't help that we were pregnant again at that point - I had the Mirena put in after the abortion and 6 months later it failed... I clearly do not have much luck with birth control! I kept thinking about how my marriage was fine again and this next baby was being kept as I hadn't been able to terminate again. I felt so much guilt.
The hardest thing I found about my termination was that there seems to be so little place for those that have a termination to grieve and find comfort. There were chat room by the dozen for those that miscarry, or terminate due to baby's illness, but where was there for me to grieve? It is an unspoken thing, a guilty thing, people don't want to hear about regrets, they want to blame you.
Well, I finally found a forum for those that have been through termination and it was a great place for me to heal myself.
This is the website:-
www.afterabortion.com/testimonials.html
It is not pro life, it is a place for women who have grief or guilt or those that don't feel anything either way, just to talk about their experiences and talk to one another. I haven't been there in a year, because my last child is now 2 and I feel a lot better. But I do remember the baby I never had every so often, and the 6+4 days he lived before I terminated the pregnancy is ingrained in my heart.
Be good to yourself, and don't be afraid to ask for help if you feel bad. And don't ever feel you made the wrong choice, if it is right for you, now.