It's incredibly common for women to feel relief, even extraordinary relief, after an abortion and then to have a traumatic reaction hit here at some future time. Some folks believe that when negative emotions settle in, it's because the woman in the meantime has been exposed to different ways of viewing abortion, or to shaming comments from others about abortion.
This article at Mental Health Matters about guilt, specifically the section on Survivor's Guilt, suggests a different picture of the relief-followed-by-distress scenario.
For some of those directly exposed to life threatening events, at least temporarily, there may be elation over having survived. For those affected by the event, traumatic symptoms may appear initially or after the elation subsides. For example, Ben had to keep moving, as quickly as possible, down the World Trade Center stairs in order to survive. Initially, thinking there was no danger, some well-meaning individuals (including his supervisor) sent people back to their offices. Ben had followed a "gut feeling" and left. A large group of other people rushed down along side of him. At one point, a number of people were killed when fire came blazing out of an elevator shaft. Ben barely escaped injury and kept rushing down the stairs. For the first few weeks, Ben was elated to be alive. About a month later, nightmares, repeated mental images of the horrors he had witnessed and other symptoms began to undermine his life.Interesting thought about how trauma symptoms are connected to being unable to overcome "the bad guys". In abortion stories, this often comes out in those who are very upset and furious with themselves because they were unable to overcome the pressure of others to abort.
After someone dies and after traumatic events, "survivor guilt" may occur because (a) individuals feel guilty for surviving or being uninjured when others were killed or injured; (b) they were unable to rescue someone or had to leave someone dying in the disaster; or (c) it was not possible to overcome "the bad guys" (Holen, 1993; Simpson, 1993). Survivors who went through the event may feel guilt because of a notion that bad things happen to people who deserve them and/or because of fear that persuades us to blame the victim (Jenkins, 1985). They also may feel guilt for being unable to control trauma symptoms (Schiraldi, 2000).